A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Ono, Y. Abe, K. Shikama, T. Takahashi, M. Yamada, K. Takenaga, and S. Matsuo, “Amplification method for crosstalk reduction in multi-core fibre amplifier,” Electron. Lett., vol. 49, no. 2, pp. 138–140, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

P. Sillard, D. Molin, M. BigotAstruc, K. de Jongh, F. Achten, “Low-differential-mode-group-delay 9-LP-mode fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper M2C.2.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Trench-assisted low-crosstalk few-mode multicore fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.5.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Investigation of crosstalk dependencies on bending radius of heterogeneous multicore fiber,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.3.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Crosstalk behavior of cores in multi-core fiber under bent condition,” IEICE Electron. Exp., vol. 8, no. 6, pp. 385–390, 2011.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “An investigation on crosstalk in multi-core fibers by introducing random fluctuation along longitudinal direction,” IEICE Trans. Commun., vol. E94-B, no. 2, pp. 409–416, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” Opt. Exp., vol. 19, no. 26, pp. B542–B550, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Large-effective-area ten-core fiber with cladding diameter of about 200 μm,” Opt. Lett., vol. 36, no. 23, pp. 4626–4628, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.2.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by trench-assisted multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper OWJ4.

S. O. Arik, J. M. Kahn, and K.-P. Ho, “MIMO signal processing for mode-division multiplexing,” IEEE Signal Process. Mag., vol. 31, no. 2, pp. 25–34, 2014.

T. Ito, E. L. T. de Gabory, M. Arikawa, Y. Hashimoto, and K. Fukuchi, “Reduction of influence of inter-core cross-talk in MCF with bidirectional assignment between neighboring cores,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.2.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

J. Sakaguchi, Y. Awaji, and N. Wada, “Fundamental study on new characterization method for crosstalk property on multi-core fibers using long wavelength probe signals,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OW1K.1.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

C. Xia, N. Bai, I. Ozdur, X. Zhou, and G. Li, “Supermodes for optical transmission,” Opt. Exp., vol. 19, no. 17, pp. 16653–16664, 2011.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

P. Sillard, D. Molin, M. BigotAstruc, K. de Jongh, F. Achten, “Low-differential-mode-group-delay 9-LP-mode fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper M2C.2.

P. Sillard, M. Bigot-Astruc, and D. Molin, “Few-mode fibers for mode-division-multiplexed systems,” J. Lightw. Technol., vol. 32, no. 16, pp. 2824–2829, 2014.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

T. Ito, E. L. T. de Gabory, M. Arikawa, Y. Hashimoto, and K. Fukuchi, “Reduction of influence of inter-core cross-talk in MCF with bidirectional assignment between neighboring cores,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.2.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

P. Sillard, D. Molin, M. BigotAstruc, K. de Jongh, F. Achten, “Low-differential-mode-group-delay 9-LP-mode fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper M2C.2.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

E. B. Desurvire, “Capacity demand and technology challenges for lightwave systems in the next two decades,” J. Lightw. Technol., vol. 24, no. 12, pp. 4697–4710, 2006.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

P. J. Winzer, A. H. Gnauck, A. Konczykowska, F. Jorge, and J. -Y. Dupuy, “Penalties from in-band crosstalk for advanced optical modulation formats,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Tu.5.B.7.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

R.-J. Essiambre, G. Kramer, P. J. Winzer, G. J. Foschini, and B. Goebel, “Capacity limits of optical fiber networks,” J. Lightw. Technol., vol. 28, no. 4, pp. 662–701, 2010.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

J. M. Fini, B. Zhu, T. F. Taunay, and M. F. Yan, “Statistics of crosstalk in bent multicore fibers,” Opt. Exp., vol. 18, pp. 15122–15129, 2010.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

R.-J. Essiambre, G. Kramer, P. J. Winzer, G. J. Foschini, and B. Goebel, “Capacity limits of optical fiber networks,” J. Lightw. Technol., vol. 28, no. 4, pp. 662–701, 2010.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

T. Ito, E. L. T. de Gabory, M. Arikawa, Y. Hashimoto, and K. Fukuchi, “Reduction of influence of inter-core cross-talk in MCF with bidirectional assignment between neighboring cores,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

B. Yao, K. Ohsono, N. Shiina, K. Fukuzato, A. Hongo, E. H. Sekiya, and K. Saito, “Reduction of crosstalk by hole-walled multi-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.5.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

P. J. Winzer, A. H. Gnauck, A. Konczykowska, F. Jorge, and J. -Y. Dupuy, “Penalties from in-band crosstalk for advanced optical modulation formats,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Tu.5.B.7.

R.-J. Essiambre, G. Kramer, P. J. Winzer, G. J. Foschini, and B. Goebel, “Capacity limits of optical fiber networks,” J. Lightw. Technol., vol. 28, no. 4, pp. 662–701, 2010.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

L. Gruner-Nielsen, Y. Sum, J. W. Nicholson, D. Jakobsen, R. Lingle, and B. Palsdottir, “Few mode transmission fiber with low DGD, low mode coupling and low loss,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5A.1.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

Y. Sasaki, K. Takenaga, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Large-effective-area uncoupled few-mode multi-core fiber,” Opt. Exp., vol. 20, no. 26, pp. B77–B84, 2012.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “An investigation on crosstalk in multi-core fibers by introducing random fluctuation along longitudinal direction,” IEICE Trans. Commun., vol. E94-B, no. 2, pp. 409–416, 2011.

K. Takenaga, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by quasi-homogeneous solid multi-core fiber,” presented at the Opt. Fiber Commun. Conf., San Diego, CA, USA, 2010, Paper OWK7.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by trench-assisted multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper OWJ4.

T. Sakamoto, K. Saitoh, N. Hanzawa, K. Tsujikawa, L. Ma, M. Koshiba, and F. Yamamoto, “Crosstalk suppressed hole-assisted 6-core fiber with cladding diameter of 125 μm,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.3.

T. Ito, E. L. T. de Gabory, M. Arikawa, Y. Hashimoto, and K. Fukuchi, “Reduction of influence of inter-core cross-talk in MCF with bidirectional assignment between neighboring cores,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.2.

T. Hayashi, T. Sasaki, E. Sasaoka, K. Saitoh, and M. Koshiba, “Physical interpretation of intercore crosstalk in multicore fiber: Effects of macrobend, structure fluctuation, and microbend,” Opt. Exp., vol. 21, no. 5, pp. 5401–5412, 2013.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Characterization of crosstalk in ultra-low-crosstalk multi-core fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 583–589, 2012.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16576–16592, 2011.

T. Hayashi, T. Nagashima, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Crosstalk variation of multi-core fiber due to fiber bend,” presented at the Eur. Conf. Opt. Commun., Torino, Italy, 2010, Paper We.8.F.6.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Ultra-low-crosstalk multi-core fiber feasible to ultra-long-haul transmission,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPC2.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

S. Matsuo, M. Ikeda, and K. Himeno, “Low-bending-loss and suppressed-splice-loss optical fibers for FTTH indoor wiring,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2004, Paper ThI3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

S. O. Arik, J. M. Kahn, and K.-P. Ho, “MIMO signal processing for mode-division multiplexing,” IEEE Signal Process. Mag., vol. 31, no. 2, pp. 25–34, 2014.

K.-P. Ho and J. M. Kahn “Statistics of group delays in multimode fiber with strong mode coupling,” J. Lightw. Technol., vol. 29, no. 21, pp. 3119–3128, 2011.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

B. Yao, K. Ohsono, N. Shiina, K. Fukuzato, A. Hongo, E. H. Sekiya, and K. Saito, “Reduction of crosstalk by hole-walled multi-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.5.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

D. Qian, M.-F. Huang, E. Ip, Y.-K. Huang, Y. Shao, J. Hu, and T. Wang, “101.7-Tb/s (370×294-Gb/s) PDM-128QAM-OFDM transmission over 3×55-km SSMF using pilot-based phase noise mitigation,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB5.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

D. Qian, M.-F. Huang, E. Ip, Y.-K. Huang, Y. Shao, J. Hu, and T. Wang, “101.7-Tb/s (370×294-Gb/s) PDM-128QAM-OFDM transmission over 3×55-km SSMF using pilot-based phase noise mitigation,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB5.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

D. Qian, M.-F. Huang, E. Ip, Y.-K. Huang, Y. Shao, J. Hu, and T. Wang, “101.7-Tb/s (370×294-Gb/s) PDM-128QAM-OFDM transmission over 3×55-km SSMF using pilot-based phase noise mitigation,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB5.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

S. Matsuo, M. Ikeda, and K. Himeno, “Low-bending-loss and suppressed-splice-loss optical fibers for FTTH indoor wiring,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2004, Paper ThI3.

K. Mukasa, K Imamura, and R. Sugizaki, “Multi-core few-mode optical fibers with large Aeff,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper P1.08.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Imamura, K. Mukasa, and R. Sugizaki, “Trench assisted multi-core fiber with large Aeff over 100 μm2 and low attenuation loss,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.1.

K. Mukasa, K. Imamura, and R. Sugizaki, “7-core 2-mode fibers with large Aeff to simultaneously realize “3M”,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper 5C1-1.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

S. Inao, T. Sato, S. Sentsui, T. Kuroha, and Y. Nishimura, “Multicore optical fiber,” presented at the Opt. Fiber Commun. Conf., Washington, DC, USA, 1979, Paper WB1.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

D. Qian, M.-F. Huang, E. Ip, Y.-K. Huang, Y. Shao, J. Hu, and T. Wang, “101.7-Tb/s (370×294-Gb/s) PDM-128QAM-OFDM transmission over 3×55-km SSMF using pilot-based phase noise mitigation,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB5.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

T. Ito, E. L. T. de Gabory, M. Arikawa, Y. Hashimoto, and K. Fukuchi, “Reduction of influence of inter-core cross-talk in MCF with bidirectional assignment between neighboring cores,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.2.

L. Gruner-Nielsen, Y. Sum, J. W. Nicholson, D. Jakobsen, R. Lingle, and B. Palsdottir, “Few mode transmission fiber with low DGD, low mode coupling and low loss,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5A.1.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

P. J. Winzer, A. H. Gnauck, A. Konczykowska, F. Jorge, and J. -Y. Dupuy, “Penalties from in-band crosstalk for advanced optical modulation formats,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Tu.5.B.7.

S. O. Arik, J. M. Kahn, and K.-P. Ho, “MIMO signal processing for mode-division multiplexing,” IEEE Signal Process. Mag., vol. 31, no. 2, pp. 25–34, 2014.

K.-P. Ho and J. M. Kahn “Statistics of group delays in multimode fiber with strong mode coupling,” J. Lightw. Technol., vol. 29, no. 21, pp. 3119–3128, 2011.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

A. Sano, H. Takara, T. Kobayashi, and Y. Miyamoto, “Crosstalk-managed high capacity long haul multicore fiber transmission with propagation-direction interleaving,” J. Lightw. Technol., vol. 30, no. 16, pp. 2771–2779, 2014.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

M. Koshiba, K. Saitoh, and Y. Kokubun, “Heterogeneous multi-core fibers: proposal and design principle,” IEICE Electron. Exp., vol. 6, no. 2, pp. 98–103, 2009.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

P. J. Winzer, A. H. Gnauck, A. Konczykowska, F. Jorge, and J. -Y. Dupuy, “Penalties from in-band crosstalk for advanced optical modulation formats,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Tu.5.B.7.

T. Hayashi, T. Sasaki, E. Sasaoka, K. Saitoh, and M. Koshiba, “Physical interpretation of intercore crosstalk in multicore fiber: Effects of macrobend, structure fluctuation, and microbend,” Opt. Exp., vol. 21, no. 5, pp. 5401–5412, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

K. Saitoh, M. Koshiba, K. Takenaga, and S. Matsuo, “Crosstalk and core density in uncoupled multi-core fibers,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1898–1901, 2012.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Analytical expression of average power-coupling coefficients for estimating intercore crosstalk in multicore fibers,” IEEE Photon. J., vol. 4, no. 5, pp. 1987–1995, 2012.

Y. Sasaki, K. Takenaga, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Large-effective-area uncoupled few-mode multi-core fiber,” Opt. Exp., vol. 20, no. 26, pp. B77–B84, 2012.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “An investigation on crosstalk in multi-core fibers by introducing random fluctuation along longitudinal direction,” IEICE Trans. Commun., vol. E94-B, no. 2, pp. 409–416, 2011.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Multi-core fiber design and analysis: Coupled-mode theory and coupled-power theory,” Opt. Exp., vol. 19, no. 26, pp. B102–B111, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Crosstalk behavior of cores in multi-core fiber under bent condition,” IEICE Electron. Exp., vol. 8, no. 6, pp. 385–390, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” Opt. Exp., vol. 19, no. 26, pp. B542–B550, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Large-effective-area ten-core fiber with cladding diameter of about 200 μm,” Opt. Lett., vol. 36, no. 23, pp. 4626–4628, 2011.

M. Koshiba, K. Saitoh, and Y. Kokubun, “Heterogeneous multi-core fibers: proposal and design principle,” IEICE Electron. Exp., vol. 6, no. 2, pp. 98–103, 2009.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Investigation of crosstalk dependencies on bending radius of heterogeneous multicore fiber,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.3.

T. Sakamoto, K. Saitoh, N. Hanzawa, K. Tsujikawa, L. Ma, M. Koshiba, and F. Yamamoto, “Crosstalk suppressed hole-assisted 6-core fiber with cladding diameter of 125 μm,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.3.

K. Takenaga, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by quasi-homogeneous solid multi-core fiber,” presented at the Opt. Fiber Commun. Conf., San Diego, CA, USA, 2010, Paper OWK7.

K. Saitoh, T. Matsui, T. Sakamoto, M. Koshiba, and S. Tomita, “Multi-core hole-assisted fibers for high core density space division multiplexing,” presented at the OptoElectron. Commun. Conf., Sapporo, Japan, 2010, Paper 7C2–1.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by trench-assisted multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper OWJ4.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.2.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Trench-assisted low-crosstalk few-mode multicore fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.5.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

N. Okada, M. Yamanaka, Y. Sato, H. Watanabe, O. Koyasu, and M. Miyamoto, “Study of the SZ-slotted rod type optical cable with the 4-fiber ribbons for aerial aplications,” in Proc. Int. Wire Cable Symp., 1997, pp. 785–792.

R.-J. Essiambre, G. Kramer, P. J. Winzer, G. J. Foschini, and B. Goebel, “Capacity limits of optical fiber networks,” J. Lightw. Technol., vol. 28, no. 4, pp. 662–701, 2010.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

S. Inao, T. Sato, S. Sentsui, T. Kuroha, and Y. Nishimura, “Multicore optical fiber,” presented at the Opt. Fiber Commun. Conf., Washington, DC, USA, 1979, Paper WB1.

R. Maruyama, M. Ohashi, K. Sato, S. Matsuo, and N. Kuwaki, “Optimized graded index two-mode optical fiber with low DMD, large Aeff and low bending loss,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper PDP2-3.

R. Maruyama, N. Kuwaki, S. Matsuo, K. Sato, and M. Ohashi, “Mode dispersion compensating optical transmission line composed of two-mode optical fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper JW2A.13.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

C. Xia, N. Bai, I. Ozdur, X. Zhou, and G. Li, “Supermodes for optical transmission,” Opt. Exp., vol. 19, no. 17, pp. 16653–16664, 2011.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

L. Gruner-Nielsen, Y. Sum, J. W. Nicholson, D. Jakobsen, R. Lingle, and B. Palsdottir, “Few mode transmission fiber with low DGD, low mode coupling and low loss,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5A.1.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

T. Sakamoto, K. Saitoh, N. Hanzawa, K. Tsujikawa, L. Ma, M. Koshiba, and F. Yamamoto, “Crosstalk suppressed hole-assisted 6-core fiber with cladding diameter of 125 μm,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.3.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

D. Marcuse, “Derivation of coupled power equations,” Bell Syst. Tech. J., vol. 51, no. 1, pp. 229–237, 1972.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

R. Maruyama, M. Ohashi, K. Sato, S. Matsuo, and N. Kuwaki, “Optimized graded index two-mode optical fiber with low DMD, large Aeff and low bending loss,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper PDP2-3.

R. Maruyama, N. Kuwaki, S. Matsuo, K. Sato, and M. Ohashi, “Mode dispersion compensating optical transmission line composed of two-mode optical fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper JW2A.13.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

K. Saitoh, T. Matsui, T. Sakamoto, M. Koshiba, and S. Tomita, “Multi-core hole-assisted fibers for high core density space division multiplexing,” presented at the OptoElectron. Commun. Conf., Sapporo, Japan, 2010, Paper 7C2–1.

H. Ono, Y. Abe, K. Shikama, T. Takahashi, M. Yamada, K. Takenaga, and S. Matsuo, “Amplification method for crosstalk reduction in multi-core fibre amplifier,” Electron. Lett., vol. 49, no. 2, pp. 138–140, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

K. Saitoh, M. Koshiba, K. Takenaga, and S. Matsuo, “Crosstalk and core density in uncoupled multi-core fibers,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1898–1901, 2012.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Analytical expression of average power-coupling coefficients for estimating intercore crosstalk in multicore fibers,” IEEE Photon. J., vol. 4, no. 5, pp. 1987–1995, 2012.

Y. Sasaki, K. Takenaga, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Large-effective-area uncoupled few-mode multi-core fiber,” Opt. Exp., vol. 20, no. 26, pp. B77–B84, 2012.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “An investigation on crosstalk in multi-core fibers by introducing random fluctuation along longitudinal direction,” IEICE Trans. Commun., vol. E94-B, no. 2, pp. 409–416, 2011.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Multi-core fiber design and analysis: Coupled-mode theory and coupled-power theory,” Opt. Exp., vol. 19, no. 26, pp. B102–B111, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Crosstalk behavior of cores in multi-core fiber under bent condition,” IEICE Electron. Exp., vol. 8, no. 6, pp. 385–390, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” Opt. Exp., vol. 19, no. 26, pp. B542–B550, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Large-effective-area ten-core fiber with cladding diameter of about 200 μm,” Opt. Lett., vol. 36, no. 23, pp. 4626–4628, 2011.

S. Matsuo, K. Takenaga, K. Saitoh, K. Nakajima, Y. Miyamoto, T. Morioka, “High-spatial-multiplicity multi-core fibres for future dense space-division-multiplexing system,” presented at the Eur. Conf. Opt. Commun., Valencia, Spain, 2015, Paper Th.1.2.1.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.2.

R. Maruyama, N. Kuwaki, S. Matsuo, K. Sato, and M. Ohashi, “Mode dispersion compensating optical transmission line composed of two-mode optical fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper JW2A.13.

R. Maruyama, M. Ohashi, K. Sato, S. Matsuo, and N. Kuwaki, “Optimized graded index two-mode optical fiber with low DMD, large Aeff and low bending loss,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper PDP2-3.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Investigation of crosstalk dependencies on bending radius of heterogeneous multicore fiber,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.3.

S. Matsuo, M. Ikeda, and K. Himeno, “Low-bending-loss and suppressed-splice-loss optical fibers for FTTH indoor wiring,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2004, Paper ThI3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

K. Takenaga, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by quasi-homogeneous solid multi-core fiber,” presented at the Opt. Fiber Commun. Conf., San Diego, CA, USA, 2010, Paper OWK7.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by trench-assisted multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper OWJ4.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Trench-assisted low-crosstalk few-mode multicore fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.5.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

N. Okada, M. Yamanaka, Y. Sato, H. Watanabe, O. Koyasu, and M. Miyamoto, “Study of the SZ-slotted rod type optical cable with the 4-fiber ribbons for aerial aplications,” in Proc. Int. Wire Cable Symp., 1997, pp. 785–792.

A. Sano, H. Takara, T. Kobayashi, and Y. Miyamoto, “Crosstalk-managed high capacity long haul multicore fiber transmission with propagation-direction interleaving,” J. Lightw. Technol., vol. 30, no. 16, pp. 2771–2779, 2014.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

S. Matsuo, K. Takenaga, K. Saitoh, K. Nakajima, Y. Miyamoto, T. Morioka, “High-spatial-multiplicity multi-core fibres for future dense space-division-multiplexing system,” presented at the Eur. Conf. Opt. Commun., Valencia, Spain, 2015, Paper Th.1.2.1.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

P. Sillard, M. Bigot-Astruc, and D. Molin, “Few-mode fibers for mode-division-multiplexed systems,” J. Lightw. Technol., vol. 32, no. 16, pp. 2824–2829, 2014.

P. Sillard, D. Molin, M. BigotAstruc, K. de Jongh, F. Achten, “Low-differential-mode-group-delay 9-LP-mode fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper M2C.2.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

T. Sakamoto, T. Mori, T. Yamamoto, and S. Tomita, “Differential mode delay managed transmission line for wide-band WDM-MIMO system,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.1.

F. Ye, J. Tu, K. Saitoh, and T. Morioka, “A simple analytical expression for crosstalk estimation in homogeneous trench-assisted multi-core fibers,” Opt. Exp., vol. 22, no. 19, pp. 23007–23018, 2014.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

T. Morioka, “New generation optical infrastructure technologies: “EXAT initiative” towards 2020 and beyond,” presented at the OptoElectron. Commun. Conf., Hong Kong, 2009, Paper FT4.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

S. Matsuo, K. Takenaga, K. Saitoh, K. Nakajima, Y. Miyamoto, T. Morioka, “High-spatial-multiplicity multi-core fibres for future dense space-division-multiplexing system,” presented at the Eur. Conf. Opt. Commun., Valencia, Spain, 2015, Paper Th.1.2.1.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

K. Imamura, K. Mukasa, and R. Sugizaki, “Trench assisted multi-core fiber with large Aeff over 100 μm2 and low attenuation loss,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.1.

K. Mukasa, K Imamura, and R. Sugizaki, “Multi-core few-mode optical fibers with large Aeff,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper P1.08.

K. Mukasa, K. Imamura, and R. Sugizaki, “7-core 2-mode fibers with large Aeff to simultaneously realize “3M”,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper 5C1-1.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

T. Hayashi, T. Nagashima, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Crosstalk variation of multi-core fiber due to fiber bend,” presented at the Eur. Conf. Opt. Commun., Torino, Italy, 2010, Paper We.8.F.6.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

S. Matsuo, K. Takenaga, K. Saitoh, K. Nakajima, Y. Miyamoto, T. Morioka, “High-spatial-multiplicity multi-core fibres for future dense space-division-multiplexing system,” presented at the Eur. Conf. Opt. Commun., Valencia, Spain, 2015, Paper Th.1.2.1.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

L. Gruner-Nielsen, Y. Sum, J. W. Nicholson, D. Jakobsen, R. Lingle, and B. Palsdottir, “Few mode transmission fiber with low DGD, low mode coupling and low loss,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5A.1.

S. Inao, T. Sato, S. Sentsui, T. Kuroha, and Y. Nishimura, “Multicore optical fiber,” presented at the Opt. Fiber Commun. Conf., Washington, DC, USA, 1979, Paper WB1.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

R. Maruyama, N. Kuwaki, S. Matsuo, K. Sato, and M. Ohashi, “Mode dispersion compensating optical transmission line composed of two-mode optical fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper JW2A.13.

R. Maruyama, M. Ohashi, K. Sato, S. Matsuo, and N. Kuwaki, “Optimized graded index two-mode optical fiber with low DMD, large Aeff and low bending loss,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper PDP2-3.

B. Yao, K. Ohsono, N. Shiina, K. Fukuzato, A. Hongo, E. H. Sekiya, and K. Saito, “Reduction of crosstalk by hole-walled multi-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.5.

N. Okada, M. Yamanaka, Y. Sato, H. Watanabe, O. Koyasu, and M. Miyamoto, “Study of the SZ-slotted rod type optical cable with the 4-fiber ribbons for aerial aplications,” in Proc. Int. Wire Cable Symp., 1997, pp. 785–792.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

H. Ono, Y. Abe, K. Shikama, T. Takahashi, M. Yamada, K. Takenaga, and S. Matsuo, “Amplification method for crosstalk reduction in multi-core fibre amplifier,” Electron. Lett., vol. 49, no. 2, pp. 138–140, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

C. Xia, N. Bai, I. Ozdur, X. Zhou, and G. Li, “Supermodes for optical transmission,” Opt. Exp., vol. 19, no. 17, pp. 16653–16664, 2011.

L. Gruner-Nielsen, Y. Sum, J. W. Nicholson, D. Jakobsen, R. Lingle, and B. Palsdottir, “Few mode transmission fiber with low DGD, low mode coupling and low loss,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5A.1.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

D. Qian, M.-F. Huang, E. Ip, Y.-K. Huang, Y. Shao, J. Hu, and T. Wang, “101.7-Tb/s (370×294-Gb/s) PDM-128QAM-OFDM transmission over 3×55-km SSMF using pilot-based phase noise mitigation,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB5.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

B. Yao, K. Ohsono, N. Shiina, K. Fukuzato, A. Hongo, E. H. Sekiya, and K. Saito, “Reduction of crosstalk by hole-walled multi-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.5.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

F. Ye, J. Tu, K. Saitoh, and T. Morioka, “A simple analytical expression for crosstalk estimation in homogeneous trench-assisted multi-core fibers,” Opt. Exp., vol. 22, no. 19, pp. 23007–23018, 2014.

T. Hayashi, T. Sasaki, E. Sasaoka, K. Saitoh, and M. Koshiba, “Physical interpretation of intercore crosstalk in multicore fiber: Effects of macrobend, structure fluctuation, and microbend,” Opt. Exp., vol. 21, no. 5, pp. 5401–5412, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

K. Saitoh, M. Koshiba, K. Takenaga, and S. Matsuo, “Crosstalk and core density in uncoupled multi-core fibers,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1898–1901, 2012.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Analytical expression of average power-coupling coefficients for estimating intercore crosstalk in multicore fibers,” IEEE Photon. J., vol. 4, no. 5, pp. 1987–1995, 2012.

Y. Sasaki, K. Takenaga, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Large-effective-area uncoupled few-mode multi-core fiber,” Opt. Exp., vol. 20, no. 26, pp. B77–B84, 2012.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “An investigation on crosstalk in multi-core fibers by introducing random fluctuation along longitudinal direction,” IEICE Trans. Commun., vol. E94-B, no. 2, pp. 409–416, 2011.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Multi-core fiber design and analysis: Coupled-mode theory and coupled-power theory,” Opt. Exp., vol. 19, no. 26, pp. B102–B111, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Crosstalk behavior of cores in multi-core fiber under bent condition,” IEICE Electron. Exp., vol. 8, no. 6, pp. 385–390, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” Opt. Exp., vol. 19, no. 26, pp. B542–B550, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Large-effective-area ten-core fiber with cladding diameter of about 200 μm,” Opt. Lett., vol. 36, no. 23, pp. 4626–4628, 2011.

M. Koshiba, K. Saitoh, and Y. Kokubun, “Heterogeneous multi-core fibers: proposal and design principle,” IEICE Electron. Exp., vol. 6, no. 2, pp. 98–103, 2009.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Investigation of crosstalk dependencies on bending radius of heterogeneous multicore fiber,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.3.

T. Sakamoto, K. Saitoh, N. Hanzawa, K. Tsujikawa, L. Ma, M. Koshiba, and F. Yamamoto, “Crosstalk suppressed hole-assisted 6-core fiber with cladding diameter of 125 μm,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

K. Takenaga, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by quasi-homogeneous solid multi-core fiber,” presented at the Opt. Fiber Commun. Conf., San Diego, CA, USA, 2010, Paper OWK7.

K. Saitoh, T. Matsui, T. Sakamoto, M. Koshiba, and S. Tomita, “Multi-core hole-assisted fibers for high core density space division multiplexing,” presented at the OptoElectron. Commun. Conf., Sapporo, Japan, 2010, Paper 7C2–1.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by trench-assisted multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper OWJ4.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.2.

S. Matsuo, K. Takenaga, K. Saitoh, K. Nakajima, Y. Miyamoto, T. Morioka, “High-spatial-multiplicity multi-core fibres for future dense space-division-multiplexing system,” presented at the Eur. Conf. Opt. Commun., Valencia, Spain, 2015, Paper Th.1.2.1.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Trench-assisted low-crosstalk few-mode multicore fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.5.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

J. Sakaguchi, Y. Awaji, and N. Wada, “Fundamental study on new characterization method for crosstalk property on multi-core fibers using long wavelength probe signals,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OW1K.1.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

T. Sakamoto, T. Mori, T. Yamamoto, and S. Tomita, “Differential mode delay managed transmission line for wide-band WDM-MIMO system,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.1.

K. Saitoh, T. Matsui, T. Sakamoto, M. Koshiba, and S. Tomita, “Multi-core hole-assisted fibers for high core density space division multiplexing,” presented at the OptoElectron. Commun. Conf., Sapporo, Japan, 2010, Paper 7C2–1.

T. Sakamoto, K. Saitoh, N. Hanzawa, K. Tsujikawa, L. Ma, M. Koshiba, and F. Yamamoto, “Crosstalk suppressed hole-assisted 6-core fiber with cladding diameter of 125 μm,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.3.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

A. Sano, H. Takara, T. Kobayashi, and Y. Miyamoto, “Crosstalk-managed high capacity long haul multicore fiber transmission with propagation-direction interleaving,” J. Lightw. Technol., vol. 30, no. 16, pp. 2771–2779, 2014.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

T. Hayashi, T. Sasaki, E. Sasaoka, K. Saitoh, and M. Koshiba, “Physical interpretation of intercore crosstalk in multicore fiber: Effects of macrobend, structure fluctuation, and microbend,” Opt. Exp., vol. 21, no. 5, pp. 5401–5412, 2013.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Characterization of crosstalk in ultra-low-crosstalk multi-core fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 583–589, 2012.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16576–16592, 2011.

T. Hayashi, T. Nagashima, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Crosstalk variation of multi-core fiber due to fiber bend,” presented at the Eur. Conf. Opt. Commun., Torino, Italy, 2010, Paper We.8.F.6.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Ultra-low-crosstalk multi-core fiber feasible to ultra-long-haul transmission,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPC2.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

Y. Sasaki, K. Takenaga, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Large-effective-area uncoupled few-mode multi-core fiber,” Opt. Exp., vol. 20, no. 26, pp. B77–B84, 2012.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” Opt. Exp., vol. 19, no. 26, pp. B542–B550, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Large-effective-area ten-core fiber with cladding diameter of about 200 μm,” Opt. Lett., vol. 36, no. 23, pp. 4626–4628, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Crosstalk behavior of cores in multi-core fiber under bent condition,” IEICE Electron. Exp., vol. 8, no. 6, pp. 385–390, 2011.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Investigation of crosstalk dependencies on bending radius of heterogeneous multicore fiber,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.3.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.2.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Trench-assisted low-crosstalk few-mode multicore fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.5.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

T. Hayashi, T. Sasaki, E. Sasaoka, K. Saitoh, and M. Koshiba, “Physical interpretation of intercore crosstalk in multicore fiber: Effects of macrobend, structure fluctuation, and microbend,” Opt. Exp., vol. 21, no. 5, pp. 5401–5412, 2013.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Characterization of crosstalk in ultra-low-crosstalk multi-core fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 583–589, 2012.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16576–16592, 2011.

T. Hayashi, T. Nagashima, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Crosstalk variation of multi-core fiber due to fiber bend,” presented at the Eur. Conf. Opt. Commun., Torino, Italy, 2010, Paper We.8.F.6.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Ultra-low-crosstalk multi-core fiber feasible to ultra-long-haul transmission,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPC2.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

R. Maruyama, M. Ohashi, K. Sato, S. Matsuo, and N. Kuwaki, “Optimized graded index two-mode optical fiber with low DMD, large Aeff and low bending loss,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper PDP2-3.

R. Maruyama, N. Kuwaki, S. Matsuo, K. Sato, and M. Ohashi, “Mode dispersion compensating optical transmission line composed of two-mode optical fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper JW2A.13.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

S. Inao, T. Sato, S. Sentsui, T. Kuroha, and Y. Nishimura, “Multicore optical fiber,” presented at the Opt. Fiber Commun. Conf., Washington, DC, USA, 1979, Paper WB1.

N. Okada, M. Yamanaka, Y. Sato, H. Watanabe, O. Koyasu, and M. Miyamoto, “Study of the SZ-slotted rod type optical cable with the 4-fiber ribbons for aerial aplications,” in Proc. Int. Wire Cable Symp., 1997, pp. 785–792.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

R. Ryf, N. K. Fontaine, B. Guan, R.-J. Essiambre, S. Randel, A. H. Gnauck, S. Chandrasekhar, A. Adamiecki, G. Raybon, B. Ercan, R. P. Scott, S. J. Ben Yoo, T. Hayashi, T. Nagashima, and T. Sasaki, “1705-km transmission over coupled-core fibre supporting 6 spatial modes,” presented at the Eur. Conf. Opt. Commun., Cannes, France, 2014, Paper PD.3.2.

B. Yao, K. Ohsono, N. Shiina, K. Fukuzato, A. Hongo, E. H. Sekiya, and K. Saito, “Reduction of crosstalk by hole-walled multi-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.5.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

S. Inao, T. Sato, S. Sentsui, T. Kuroha, and Y. Nishimura, “Multicore optical fiber,” presented at the Opt. Fiber Commun. Conf., Washington, DC, USA, 1979, Paper WB1.

D. Qian, M.-F. Huang, E. Ip, Y.-K. Huang, Y. Shao, J. Hu, and T. Wang, “101.7-Tb/s (370×294-Gb/s) PDM-128QAM-OFDM transmission over 3×55-km SSMF using pilot-based phase noise mitigation,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB5.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

B. Yao, K. Ohsono, N. Shiina, K. Fukuzato, A. Hongo, E. H. Sekiya, and K. Saito, “Reduction of crosstalk by hole-walled multi-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.5.

H. Ono, Y. Abe, K. Shikama, T. Takahashi, M. Yamada, K. Takenaga, and S. Matsuo, “Amplification method for crosstalk reduction in multi-core fibre amplifier,” Electron. Lett., vol. 49, no. 2, pp. 138–140, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Characterization of crosstalk in ultra-low-crosstalk multi-core fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 583–589, 2012.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16576–16592, 2011.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Ultra-low-crosstalk multi-core fiber feasible to ultra-long-haul transmission,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPC2.

T. Hayashi, T. Nagashima, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Crosstalk variation of multi-core fiber due to fiber bend,” presented at the Eur. Conf. Opt. Commun., Torino, Italy, 2010, Paper We.8.F.6.

T. Hayashi, T. Nakanishi, K. Hirashima, O. Shimakawa, F. Sato, K. Koyama, A. Furuya, Y. Murakami, and T. Sasaki, “125-μm-cladding 8-core multi-core fiber realizing ultra-high-density cable suitable for O-band short-reach optical interconnects,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.6.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

P. Sillard, “Next-generation fibers for space-division-multiplexed transmissions,” J. Lightw. Technol., vol. 33, no. 5, pp. 1092–1099, 2015.

P. Sillard, M. Bigot-Astruc, and D. Molin, “Few-mode fibers for mode-division-multiplexed systems,” J. Lightw. Technol., vol. 32, no. 16, pp. 2824–2829, 2014.

P. Sillard, D. Molin, M. BigotAstruc, K. de Jongh, F. Achten, “Low-differential-mode-group-delay 9-LP-mode fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper M2C.2.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

K. Imamura, K. Mukasa, and R. Sugizaki, “Trench assisted multi-core fiber with large Aeff over 100 μm2 and low attenuation loss,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.1.

K. Mukasa, K. Imamura, and R. Sugizaki, “7-core 2-mode fibers with large Aeff to simultaneously realize “3M”,” presented at the OptoElectron. Commun. Conf., Busan, Korea, 2012, Paper 5C1-1.

K. Mukasa, K Imamura, and R. Sugizaki, “Multi-core few-mode optical fibers with large Aeff,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper P1.08.

L. Gruner-Nielsen, Y. Sum, J. W. Nicholson, D. Jakobsen, R. Lingle, and B. Palsdottir, “Few mode transmission fiber with low DGD, low mode coupling and low loss,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5A.1.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

H. Ono, Y. Abe, K. Shikama, T. Takahashi, M. Yamada, K. Takenaga, and S. Matsuo, “Amplification method for crosstalk reduction in multi-core fibre amplifier,” Electron. Lett., vol. 49, no. 2, pp. 138–140, 2013.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

A. Sano, H. Takara, T. Kobayashi, and Y. Miyamoto, “Crosstalk-managed high capacity long haul multicore fiber transmission with propagation-direction interleaving,” J. Lightw. Technol., vol. 30, no. 16, pp. 2771–2779, 2014.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Shibahara, T. Mizuno, H. Takara, A. Sano, H. Kawakami, D. Lee, Y. Miyamoto, H. Ono, M. Oguma, Y. Abe, T. Kobayashi, T. Matsui, R. Fukumoto, Y. Amma, T. Hosokawa, S. Matsuo, K. Saito, H. Nasu, and T. Morioka, “Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.3.

H. Ono, Y. Abe, K. Shikama, T. Takahashi, M. Yamada, K. Takenaga, and S. Matsuo, “Amplification method for crosstalk reduction in multi-core fibre amplifier,” Electron. Lett., vol. 49, no. 2, pp. 138–140, 2013.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Takara, H. Ono, Y. Abe, H. Masuda, K. Takenaga, S. Matsuo, H. Kubota, K. Shibahara, T. Kobayashi, and Y. Miyamoto, “1000-km 7-core fiber transmission of 10x 96-Gb/s PDM-16QAM using Raman amplification with 6.5W per fiber,” Opt. Exp., vol. 20, no. 9, pp. 10100–10105, 2012.

K. Saitoh, M. Koshiba, K. Takenaga, and S. Matsuo, “Crosstalk and core density in uncoupled multi-core fibers,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1898–1901, 2012.

S. Matsuo, Y. Sasaki, T. Akamatsu, I. Ishida, K. Takenaga, K. Okuyama, K Saitoh, and M. Kosihba, “12-core fiber with one ring structure for extremely large capacity Transmission,” Opt. Exp., vol. 20, no. 27, pp. 28398–28408, 2012.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Analytical expression of average power-coupling coefficients for estimating intercore crosstalk in multicore fibers,” IEEE Photon. J., vol. 4, no. 5, pp. 1987–1995, 2012.

Y. Sasaki, K. Takenaga, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Large-effective-area uncoupled few-mode multi-core fiber,” Opt. Exp., vol. 20, no. 26, pp. B77–B84, 2012.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “An investigation on crosstalk in multi-core fibers by introducing random fluctuation along longitudinal direction,” IEICE Trans. Commun., vol. E94-B, no. 2, pp. 409–416, 2011.

M. Koshiba, K. Saitoh, K. Takenaga, and S. Matsuo, “Multi-core fiber design and analysis: Coupled-mode theory and coupled-power theory,” Opt. Exp., vol. 19, no. 26, pp. B102–B111, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Crosstalk behavior of cores in multi-core fiber under bent condition,” IEICE Electron. Exp., vol. 8, no. 6, pp. 385–390, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” Opt. Exp., vol. 19, no. 26, pp. B542–B550, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Large-effective-area ten-core fiber with cladding diameter of about 200 μm,” Opt. Lett., vol. 36, no. 23, pp. 4626–4628, 2011.

S. Matsuo, K. Takenaga, K. Saitoh, K. Nakajima, Y. Miyamoto, T. Morioka, “High-spatial-multiplicity multi-core fibres for future dense space-division-multiplexing system,” presented at the Eur. Conf. Opt. Commun., Valencia, Spain, 2015, Paper Th.1.2.1.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.2.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Investigation of crosstalk dependencies on bending radius of heterogeneous multicore fiber,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OTh3K.3.

K. Takenaga, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by quasi-homogeneous solid multi-core fiber,” presented at the Opt. Fiber Commun. Conf., San Diego, CA, USA, 2010, Paper OWK7.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by trench-assisted multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper OWJ4.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

Y. Sasaki, Y. Amma, K. Takenaga, S. Matsuo, K. Saitoh, and M. Koshiba, “Trench-assisted low-crosstalk few-mode multicore fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.5.

T. Mizuno, T. Kobayashi, H. Takara, A. Sano, H. Kawakami, T. Nakagawa, Y. Miyamoto, Y. Abe, T. Goh, M. Oguma, T. Sakamoto, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, and T. Morioka, “12-core × 3-mode dense space division multiplexed transmission over 40 km employing multi-carrier signals with parallel MIMO equalization,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.2.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “An investigation on crosstalk in multi-core fibers by introducing random fluctuation along longitudinal direction,” IEICE Trans. Commun., vol. E94-B, no. 2, pp. 409–416, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Crosstalk behavior of cores in multi-core fiber under bent condition,” IEICE Electron. Exp., vol. 8, no. 6, pp. 385–390, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” Opt. Exp., vol. 19, no. 26, pp. B542–B550, 2011.

S. Matsuo, K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba, “Large-effective-area ten-core fiber with cladding diameter of about 200 μm,” Opt. Lett., vol. 36, no. 23, pp. 4626–4628, 2011.

K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, S. Matsuo, K. Saitoh, and M. Koshiba, “A large effective area multi-core fiber with an optimized cladding thickness,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Mo.1.LeCervin.2.

K. Takenaga, Y. Arakawa, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by trench-assisted multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper OWJ4.

K. Takenaga, S. Tanigawa, N. Guan, S. Matsuo, K. Saitoh, and M. Koshiba, “Reduction of crosstalk by quasi-homogeneous solid multi-core fiber,” presented at the Opt. Fiber Commun. Conf., San Diego, CA, USA, 2010, Paper OWK7.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Characterization of crosstalk in ultra-low-crosstalk multi-core fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 583–589, 2012.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16576–16592, 2011.

T. Hayashi, T. Taru, O. Shimakawa, T. Sasaki, and E. Sasaoka, “Ultra-low-crosstalk multi-core fiber feasible to ultra-long-haul transmission,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPC2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

J. M. Fini, B. Zhu, T. F. Taunay, and M. F. Yan, “Statistics of crosstalk in bent multicore fibers,” Opt. Exp., vol. 18, pp. 15122–15129, 2010.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

K. Saitoh, T. Matsui, T. Sakamoto, M. Koshiba, and S. Tomita, “Multi-core hole-assisted fibers for high core density space division multiplexing,” presented at the OptoElectron. Commun. Conf., Sapporo, Japan, 2010, Paper 7C2–1.

T. Sakamoto, T. Mori, T. Yamamoto, and S. Tomita, “Differential mode delay managed transmission line for wide-band WDM-MIMO system,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.1.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

M. Salsi, R. Rios-Muller, J. Renaudier, P. Tran, L. Schmalen, A. Ghazisaeidi, H. Mardoyan, P. Brindel, G. Charlet, and S. Bigo, “38.75 Tb/s transmission experiment over transoceanic distance,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.2.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

H. Takara, A. Sano, T. Kobayashi, H. Kubota, H. Kawakami, A. Matsuura, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, Y. Goto, K. Tsujikawa, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, and T. Morioka, “1.01-Pb/s(12 SDM/222 WDM/456 Gb/s) crosstalk-managed transmission with 91.4-b/s/Hz aggregate spectral efficiency,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.1.

T. Sakamoto, K. Saitoh, N. Hanzawa, K. Tsujikawa, L. Ma, M. Koshiba, and F. Yamamoto, “Crosstalk suppressed hole-assisted 6-core fiber with cladding diameter of 125 μm,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.3.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

F. Ye, J. Tu, K. Saitoh, and T. Morioka, “A simple analytical expression for crosstalk estimation in homogeneous trench-assisted multi-core fibers,” Opt. Exp., vol. 22, no. 19, pp. 23007–23018, 2014.

Y. Amma, Y. Sasaki, K. Takenaga, S. Matsuo, J. Tu, K.M. SaitohKoshiba, T. Morioka, and Y. Miyamoto, “High-density multicore fiber with heterogeneous core arrangement,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th4C.4.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

M. O. Van Deventer, “Polarization properties of Rayleigh backscattering in single-mode fibers,” J. Lightw. Technol., vol. 11, no. 12, pp. 1895–1899, 1993.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

J. Sakaguchi, Y. Awaji, and N. Wada, “Fundamental study on new characterization method for crosstalk property on multi-core fibers using long wavelength probe signals,” presented at the Opt. Fiber Commun. Conf., Anaheim, CA, USA, 2013, Paper OW1K.1.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

K. Igarashi, D. Souma, Y. Wakayama, K. Takeshima, Y. Kawaguchi, T. Tsuritani, I. Morita, and M. Suzuki, “114 space-division-multiplexed transmission over 9.8-km weakly-coupled-6-mode uncoupled-19-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.4.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

D. Qian, M.-F. Huang, E. Ip, Y.-K. Huang, Y. Shao, J. Hu, and T. Wang, “101.7-Tb/s (370×294-Gb/s) PDM-128QAM-OFDM transmission over 3×55-km SSMF using pilot-based phase noise mitigation,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB5.

N. Okada, M. Yamanaka, Y. Sato, H. Watanabe, O. Koyasu, and M. Miyamoto, “Study of the SZ-slotted rod type optical cable with the 4-fiber ribbons for aerial aplications,” in Proc. Int. Wire Cable Symp., 1997, pp. 785–792.

K. Igarashi, T. Tsuritani, I. Morita, Y. Tsuchida, K. Maeda, M. Tadakuma, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “1.03-Exabit/s·km super-Nyquist-WDM transmission over 7,326-km seven-core fiber,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.3.

H. Takahashi, T. Tsuritani, E. L. T. de Gabory, T. Ito, W. R. Peng, K. Igarashi, K. Takeshima, Y. Kawaguchi, I. Morita, Y. Tsuchida, Y. Mimura, K. Maeda, T. Saito, K. Watanabe, K. Imamura, R. Sugizaki, and M. Suzuki, “First demonstration of MC-EDFA-repeatered SDM transmission of 40 × 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF,” presented at the Eur. Conf. Opt. Commun., Amsterdam, The Netherlands, 2012, Paper Th.3.C.3.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Inaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “305-Tb/s space division multiplexed transmission using homogeneous 19-core fiber,” J. Lightw. Technol., vol. 31, no. 4, pp. 554–562, 2013.

J. Sakaguchi, W. Klaus, B. J. Puttnam, J. M. D. Mendinueta, Y. Awaji, N. Wada, Y. Tsuchida, K. Maeda, M. Tadakuma, K. Imamura, R. Sugizaki, T. Kobayashi, Y. Tottori, M. Watanabe, and R. V. Jensen, “19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics,” Opt. Exp., vol. 22, no. 1, pp. 90–95, 2013.

J. Sakaguchi, B. J. Puttnam, W. Klaus, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, K. Imamura, H. Unaba, K. Mukasa, R. Sugizaki, T. Kobayashi, and M. Watanabe, “19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signal at 305 Tb/s,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.1.

J. Sakaguchi, Y. Awaji, N. Wada, A. Kanno, T. Kawanishi, T. Hayashi, T. Taru, T. Kobayashi, and M. Watanabe, “109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB6.

J. Sakaguchi, W. Klaus, J.-M. D. Mendinueta, B. J. Puttnam1, R. S. Luis, Y. Awaji1, N. Wada, T. Hayashi, T. Nakanishi, T. Watanabe, Y. Kokubun, T. Takahata, and T. Kobayashi, “Realizing a 36-core, 3-mode fiber with 108 spatial channels,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.2.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

R.-J. Essiambre, G. Kramer, P. J. Winzer, G. J. Foschini, and B. Goebel, “Capacity limits of optical fiber networks,” J. Lightw. Technol., vol. 28, no. 4, pp. 662–701, 2010.

R. Ryf, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. A. Mestre, C. Schmidt, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Space-division multiplexed transmission over 4200-km 3-core microstructured fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.2.

R. Ryf, A. Sierra, R.-J. Essiambre, A. H. Gnauck, S. Randel, M. Esmaeelpour, S. Mumtaz, P. J. Winzer, R. Delbue, P. Pupalaikis, A. Sureka, T. Hayashi, T. Taru, and T. Sasaki, “Coherent 1200-km 6×6 MIMO mode-multiplexed transmission over 3-core microstructured fiber,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Th.13.C.1.

P. J. Winzer, A. H. Gnauck, A. Konczykowska, F. Jorge, and J. -Y. Dupuy, “Penalties from in-band crosstalk for advanced optical modulation formats,” presented at the Eur. Conf. Opt. Commun., Geneva, Switzerland, 2011, Paper Tu.5.B.7.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

C. Xia, N. Bai, I. Ozdur, X. Zhou, and G. Li, “Supermodes for optical transmission,” Opt. Exp., vol. 19, no. 17, pp. 16653–16664, 2011.

A. Sano, H. Takara, T. Kobayashi, H. Kawakami, H. Kisikawa, T. Nakagawa, Y. Miyamoto, Y. Abe, H. Ono, K. Shikama, M. Nagatani, T. Moro, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Koshiba, M. Yamada, H. Masuda, and T. Morioka, “409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving,” Opt. Exp., vol. 21, no. 14, pp. 16777–16783, 2013.

H. Ono, Y. Abe, K. Shikama, T. Takahashi, M. Yamada, K. Takenaga, and S. Matsuo, “Amplification method for crosstalk reduction in multi-core fibre amplifier,” Electron. Lett., vol. 49, no. 2, pp. 138–140, 2013.

T. Kobayashi, H. Takara, A. Sano, T. Mizuno, H. Kawakami, Y. Miyamoto, K. Hiraga, Y. Abe, H. Ono, M. Wada, Y. Sasaki, I. Ishida, K. Takenaga, S. Matsuo, K. Saitoh, M. Yamada, H. Masuda, and T. Morioka, “2×344 Tb/s propagation-direction interleaved transmission over 1500-km MCF enhanced by multicarrier full electric-field digital back-propagation,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.4.

T. Sakamoto, K. Saitoh, N. Hanzawa, K. Tsujikawa, L. Ma, M. Koshiba, and F. Yamamoto, “Crosstalk suppressed hole-assisted 6-core fiber with cladding diameter of 125 μm,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper Mo.3.A.3.

T. Sakamoto, T. Mori, T. Yamamoto, and S. Tomita, “Differential mode delay managed transmission line for wide-band WDM-MIMO system,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.1.

N. Okada, M. Yamanaka, Y. Sato, H. Watanabe, O. Koyasu, and M. Miyamoto, “Study of the SZ-slotted rod type optical cable with the 4-fiber ribbons for aerial aplications,” in Proc. Int. Wire Cable Symp., 1997, pp. 785–792.

A. Sano, T. Kobayashi, S. Yamanaka, A. Matsuura, H. Kawakami, Y. Miyamoto, K. Ishihara, and H. Masuda, “102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper PDP5C.3.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

J. M. Fini, B. Zhu, T. F. Taunay, and M. F. Yan, “Statistics of crosstalk in bent multicore fibers,” Opt. Exp., vol. 18, pp. 15122–15129, 2010.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

B. Yao, K. Ohsono, N. Shiina, K. Fukuzato, A. Hongo, E. H. Sekiya, and K. Saito, “Reduction of crosstalk by hole-walled multi-core fibers,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2012, Paper OM2D.5.

F. Ye, J. Tu, K. Saitoh, and T. Morioka, “A simple analytical expression for crosstalk estimation in homogeneous trench-assisted multi-core fibers,” Opt. Exp., vol. 22, no. 19, pp. 23007–23018, 2014.

S. Inao, T. Sato, H. Hondo, M. Ogai, S. Sentsui, A. Otake, K. Yoshizaki, K. Ishihara, and N. Uchida, “High density multicore-fiber cable,” in Proc. Int. Wire Cable Symp., 1979, pp. 370–384.

D. G. Foursa, H. G. Batshon, H. Zhang, M. Mazurczyk, J.-X. Cai, O. Sinkin, A. Pilipetskii, G. Mohs, and N. S. Bergano, “44.1 Tb/s transmission over 9,100 km using coded modulation based on 16QAM signals at 4.9 bits/s/Hz spectral efficiency,” presented at the Eur. Conf. Opt. Commun., London, U.K., 2013, Paper PD3.E.1.

J.-X. Cai, H. G. Batshon, M. Mazurczyk, H. Zhang, Y. Sun, O. V. Sinkin, D. Foursa, and A. N. Pilipetskii, “64QAM based coded modulation transmission over transoceanic distance with > 60 Tb/s capacity,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2015, Paper Th5C.8.

J.-X. Cai, H. Zhang, H. G. Batshon, M. Mazurczyk, O. Sinkin, Y. Sun, A. Pilipetskii, and D. Foursa, “Transmission over 9,100 km with a capacity of 49.3 Tb/s using variable spectral efficiency 16 QAM based coded modulation,” presented at the Opt. Fiber Commun. Conf., San Francisco, CA, USA, 2014, Paper Th5B.4.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

D. Qian, E. Ip, M. F. Huang, M. J. Li, A. Dogariu, S. Zhang, Y. Shao, Y. K. Huang, Y. Zhang, X. Cheng, Y. Tian, P. Ji, A. Collier, Y. Geng, J. Linares, C. Montero, V. Moreno, X. Prieto, and T. Wang, “1.05Pb/s transmission with 109b/s/Hz spectral efficiency using hybrid single- and few-mode cores,” presented at the Frontiers Opt., Rochester, NY, USA, 2012, Paper FW6C.

C. Xia, R. Amezcua-Correa, N. Bai, E. Antonio-Lopez, D. M. Arrioja, A. Schulzgen, M. Richardson, J. Linares, C. Montero, E. Mateo, X. Zhou, and G. Li, “Hole-assisted few-mode multicore fiber for high-density space-division multiplexing,” IEEE Photon. Technol. Lett., vol. 24, no. 21, pp. 1914–1917, 2012.

C. Xia, N. Bai, I. Ozdur, X. Zhou, and G. Li, “Supermodes for optical transmission,” Opt. Exp., vol. 19, no. 17, pp. 16653–16664, 2011.

S. Chandrasekhar, A. H. Gnauck, X. Liu, P. J. Winzer, Y. Pan, E. C. Burrows, T. F. Taunay, B. Zhu, M. Fishteyn, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “WDM/SDM transmission of 10x 128-Gb/s PDM-QPSK over 2688-km 7-core fiber with a per-fiber net aggregate spectral-efficiency distance product of 40,320 km b/s/Hz,” Opt. Exp., vol. 20, no. 2, pp. 706–711, 2012.

B. Zhu, J. M. Fini, M. F. Yan, X. Liu, S. Chandrasekhar, T. F. Taunay, M. Fishteyn, E. M. Monberg, and F. V. Dimarcello, “High-capacity space-division-multiplexed DWDM transmissions using multicore fiber,” J. Lightw. Technol., vol. 30, no. 4, pp. 486–492, 2012.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandraskekhar, M. F. Yan, J. M. Fini, E. M. Monberg, and F. V. Dimarcello, “112-Tb/s space-division multiplexed DWDM transmission with 14-b/s/Hz aggregate spectral efficiency over a 76.8-km seven-core fiber,” Opt. Exp., vol. 19, no. 17, pp. 16665–16671, 2011.

J. M. Fini, B. Zhu, T. F. Taunay, and M. F. Yan, “Statistics of crosstalk in bent multicore fibers,” Opt. Exp., vol. 18, pp. 15122–15129, 2010.

B. Zhu, T. F. Taunay, M. Fishteyn, X. Liu, S. Chandrasekhar, M. F. Yan, J. M. Fini, E. M. Monberg, F. V. Dimarcello, K. Abedin, P. W. Wisk, D. W. Peckham, and P. Dziedzic, “Space-, wavelength-, polarization-division multiplexed transmission of 56-Tb/s over a 76.8-km seven-core fiber,” presented at the Opt. Fiber Commun. Conf., Los Angeles, CA, USA, 2011, Paper PDPB7.

A. Ziolowicz, M. Szymanski, L. Szostkiewicz, T. Tenderenda1, M. Napierala, M. Murawski, Z. Holdynski, L. Ostrowski, P. Mergo, K. Poturaj, M. Makara, M. Slowikowski, K. Pawlik, T. Stanczyk, K. Stepien, K. Wysokinski, M. Broczkowska, and T. Nasilowski, “Hole-assisted multicore optical fiber for next generation telecom transmission systems,” Appl. Phys. Lett., vol. 105, no. 8, p. 081106, 2014.