Abstract

Fused-type mode-selective fiber couplers exciting the LP11 mode are fabricated by well-defined fiber cladding reduction, pretapering and fusion. At a wavelength of 905 nm 80 % of the injected power in the single-mode fiber was transmitted in the few-mode fiber selectively exciting the LP11 mode. The coupling behavior was experimentally investigated for the case of strong as well as weak fusion. Numerical simulations based on the super-mode coupling approach were used to estimate fabrication parameters and to discuss the modal evolution in arbitrarily fused couplers. The influence of changes in the coupler geometry on the super-modes and their modal weighting are analyzed by calculations of the effective refractive index and by modal decomposition.

© 2015 Optical Society of America

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References

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2014 (7)

2013 (5)

2012 (4)

2011 (1)

2010 (2)

2009 (1)

2008 (1)

2007 (1)

2005 (1)

2004 (2)

2003 (1)

K. Y. Song and B. Y. Kim, “Broad-band LP02 mode excitation using a fused-type mode-selective coupler,” IEEE Photon. Technol. Lett. 15, 1734–1736 (2003).
[Crossref]

2002 (1)

K. Y. Song, I. K. Hwang, S. H. Yun, and B. Y. Kim, “High performance fused-type mode-selective coupler using elliptical core two-mode fiber at 1550 nm,” IEEE Photon. Technol. Lett. 14, 501–503 (2002).
[Crossref]

1999 (1)

Y. Shou, J. Bures, S. Lacroix, and X. Daxhelet, “Mode separation in fused fiber coupler made of two-mode fibers,” Opt. Fiber Technol. 5, 92–104 (1999).
[Crossref]

1994 (1)

1988 (2)

1986 (1)

1985 (2)

1984 (1)

1981 (1)

Abebe, M.

Akamatsu, T.

Alam, S. U.

Amin, A. A.

Argyros, A.

Birks, T. A.

Bland-Hawthorn, J.

Brambilla, G.

Bures, J.

Y. Shou, J. Bures, S. Lacroix, and X. Daxhelet, “Mode separation in fused fiber coupler made of two-mode fibers,” Opt. Fiber Technol. 5, 92–104 (1999).
[Crossref]

S. Lacroix, F. Gonthier, and J. Bures, “Modeling of symmetric 2× 2 fused-fiber couplers,” Appl. Opt. 33, 8361–8369 (1994).
[Crossref] [PubMed]

Burns, W. K.

Chandrasekhar, S.

Chen, R.

Chen, S.

Chen, X.

Daxhelet, X.

Di-marcello, F. V.

Englund, M.

Ercan, B.

Essiambre, R.-J.

Fini, J. M.

Fishteyn, M.

Fontaine, N. K.

Foschini, G. J.

Gao, G.

Giles, I. P.

Goebel, B.

Gonthier, F.

Gris-Sánches, I.

Gross, S.

N. Riesen, S. Gross, J. D. Love, and M. J. Withford, “Femtosecond direct-written integrated mode couplers,” Opt. Express 22, 29855–29861 (2014).
[Crossref]

S. Gross, N. Riesen, J. D. Love, and M. J. Withford, “Three-dimensional ultra-broadband integrated tapered mode multiplexers,” Laser Photon. Rev. 8, L81–L85 (2014).
[Crossref]

Hanzawa, N.

Hausmann, K.

Hill, K. O.

Hwang, I. K.

K. Y. Song, I. K. Hwang, S. H. Yun, and B. Y. Kim, “High performance fused-type mode-selective coupler using elliptical core two-mode fiber at 1550 nm,” IEEE Photon. Technol. Lett. 14, 501–503 (2002).
[Crossref]

Ishida, I.

Ismaeel, R.

Jung, Y.

Kawasaki, B. S.

Kim, B. Y.

K. Y. Song and B. Y. Kim, “Broad-band LP02 mode excitation using a fused-type mode-selective coupler,” IEEE Photon. Technol. Lett. 15, 1734–1736 (2003).
[Crossref]

K. Y. Song, I. K. Hwang, S. H. Yun, and B. Y. Kim, “High performance fused-type mode-selective coupler using elliptical core two-mode fiber at 1550 nm,” IEEE Photon. Technol. Lett. 14, 501–503 (2002).
[Crossref]

W. V. Sorin, B. Y. Kim, and H. J. Shaw, “Highly selective evanescent modal filter for two-mode optical fibers,” Opt. Lett. 11, 581–583 (1986).
[Crossref] [PubMed]

Koshiba, M.

Kosihba, M.

Kracht, D.

Kramer, G.

Lacroix, S.

Lai, K.

Lamont, R. G.

Lee, T.

Leon-Saval, S. G.

Li, A.

Liao, Q.

Liu, K.

Liu, X.

Love, J. D.

Marcuse, D.

Matsui, T.

Matsuo, S.

McLandrich, M.

M. McLandrich, “Core dopant profiles in weakly fused single-mode fibres,” Electron. Lett. 24, 8–10 (1988).
[Crossref]

Monberg, E. M.

Morgner, U.

Mortimore, D. B.

D. B. Mortimore, “Wavelength-flattened fused couplers,” Electron. Lett. 21, 742–743 (1985).
[Crossref]

Nelson, L. E.

D. J. Richardson, J. M. Fini, and L. E. Nelson, “Space-division multiplexing in optical fibres,” Nature Photon. 7, 354–362 (2013).
[Crossref]

Neumann, J.

Nielsen, M. D.

Noordegraaf, D.

Oduro, B.

Okuyama, K.

Pelegrina-Bonilla, G.

Pham, A.

Pickett, C. W.

Pone, E.

Richardson, D. J.

Riesen, N.

Ryf, R.

Saitoh, K.

Sakamoto, T.

Salazar-Gil, J. R.

Sasaki, Y.

Sayinc, H.

Shaw, H. J.

Shieh, W.

Shou, Y.

Y. Shou, J. Bures, S. Lacroix, and X. Daxhelet, “Mode separation in fused fiber coupler made of two-mode fibers,” Opt. Fiber Technol. 5, 92–104 (1999).
[Crossref]

Skovgaard, P. M.

Song, K. Y.

K. Y. Song and B. Y. Kim, “Broad-band LP02 mode excitation using a fused-type mode-selective coupler,” IEEE Photon. Technol. Lett. 15, 1734–1736 (2003).
[Crossref]

K. Y. Song, I. K. Hwang, S. H. Yun, and B. Y. Kim, “High performance fused-type mode-selective coupler using elliptical core two-mode fiber at 1550 nm,” IEEE Photon. Technol. Lett. 14, 501–503 (2002).
[Crossref]

Sorin, W. V.

Takenaga, K.

Taunay, T. F.

Tsujikawa, K.

Tünnermann, H.

Villarruel, C. A.

Wadsworth, W. J.

Wang, Y.

Weßels, P.

Winzer, P. J.

Withford, M. J.

S. Gross, N. Riesen, J. D. Love, and M. J. Withford, “Three-dimensional ultra-broadband integrated tapered mode multiplexers,” Laser Photon. Rev. 8, L81–L85 (2014).
[Crossref]

N. Riesen, S. Gross, J. D. Love, and M. J. Withford, “Femtosecond direct-written integrated mode couplers,” Opt. Express 22, 29855–29861 (2014).
[Crossref]

Witkowska, A.

Yamamoto, F.

Yan, M. F.

Yerolatsitis, S.

Yun, S. H.

K. Y. Song, I. K. Hwang, S. H. Yun, and B. Y. Kim, “High performance fused-type mode-selective coupler using elliptical core two-mode fiber at 1550 nm,” IEEE Photon. Technol. Lett. 14, 501–503 (2002).
[Crossref]

Zhong, N.

Zhu, B.

Zhu, X.

Appl. Opt. (4)

Electron. Lett. (2)

M. McLandrich, “Core dopant profiles in weakly fused single-mode fibres,” Electron. Lett. 24, 8–10 (1988).
[Crossref]

D. B. Mortimore, “Wavelength-flattened fused couplers,” Electron. Lett. 21, 742–743 (1985).
[Crossref]

IEEE Photon. Technol. Lett. (2)

K. Y. Song, I. K. Hwang, S. H. Yun, and B. Y. Kim, “High performance fused-type mode-selective coupler using elliptical core two-mode fiber at 1550 nm,” IEEE Photon. Technol. Lett. 14, 501–503 (2002).
[Crossref]

K. Y. Song and B. Y. Kim, “Broad-band LP02 mode excitation using a fused-type mode-selective coupler,” IEEE Photon. Technol. Lett. 15, 1734–1736 (2003).
[Crossref]

J. Lightwave Technol. (5)

Laser Photon. Rev. (1)

S. Gross, N. Riesen, J. D. Love, and M. J. Withford, “Three-dimensional ultra-broadband integrated tapered mode multiplexers,” Laser Photon. Rev. 8, L81–L85 (2014).
[Crossref]

Nature Photon. (2)

P. J. Winzer, “Making spatial multiplexing a reality,” Nature Photon. 8, 345–348 (2014).
[Crossref]

D. J. Richardson, J. M. Fini, and L. E. Nelson, “Space-division multiplexing in optical fibres,” Nature Photon. 7, 354–362 (2013).
[Crossref]

Opt. Express (12)

A. A. Amin, A. Li, S. Chen, X. Chen, G. Gao, and W. Shieh, “Dual-LP11 mode 4 × 4 MIMO-OFDM transmission over a two-mode fiber,” Opt. Express 19, 16672–16679 (2011).
[Crossref] [PubMed]

N. Hanzawa, K. Saitoh, T. Sakamoto, T. Matsui, K. Tsujikawa, M. Koshiba, and F. Yamamoto, “Two-mode PLC-based mode multi/demultiplexer for mode and wavelength division multiplexed transmission,” Opt. Express 21, 25752–25760 (2013).
[Crossref] [PubMed]

N. Riesen, S. Gross, J. D. Love, and M. J. Withford, “Femtosecond direct-written integrated mode couplers,” Opt. Express 22, 29855–29861 (2014).
[Crossref]

Y. Jung, R. Chen, R. Ismaeel, G. Brambilla, S. U. Alam, I. P. Giles, and D. J. Richardson, “Dual mode fused optical fiber couplers suitable for mode division multiplexed transmission,” Opt. Express 21, 24326–24331 (2013).
[Crossref] [PubMed]

R. Ismaeel, T. Lee, B. Oduro, Y. Jung, and G. Brambilla, “All-fiber fused directional coupler for highly efficient spatial mode conversion,” Opt. Express 22, 11610–11619 (2014).
[Crossref] [PubMed]

S. G. Leon-Saval, A. Argyros, and J. Bland-Hawthorn, “Photonic lanterns: a study of light propagation in multi-mode to single-mode converters,” Opt. Express 18, 8430–8439 (2010).
[Crossref] [PubMed]

D. Noordegraaf, P. M. Skovgaard, M. D. Nielsen, and J. Bland-Hawthorn, “Efficient multi-mode to single-mode coupling in a photonic lantern,” Opt. Express 17, 1988–1994 (2009).
[Crossref] [PubMed]

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. Express 20, 28398–28408 (2012).
[Crossref] [PubMed]

S. Yerolatsitis, I. Gris-Sánches, and T. A. Birks, “Adiabatically-tapered fiber mode multiplexers,” Opt. Express 22, 608–617 (2014).
[Crossref] [PubMed]

E. Pone, X. Daxhelet, and S. Lacroix, “Refractive index profile of fused-fiber couplers cross-section,” Opt. Express 12, 1036–1044 (2004).
[Crossref] [PubMed]

E. Pone, X. Daxhelet, and S. Lacroix, “Refractive index profile of fused-tapered fiber couplers,” Opt. Express 12, 2909–2918 (2004).
[Crossref] [PubMed]

S. G. Leon-Saval, N. K. Fontaine, J. R. Salazar-Gil, B. Ercan, R. Ryf, and J. Bland-Hawthorn, “Mode-selective photonic lanterns for space-division multiplexing,” Opt. Express 22, 1036–1044 (2014).
[Crossref] [PubMed]

Opt. Fiber Technol. (1)

Y. Shou, J. Bures, S. Lacroix, and X. Daxhelet, “Mode separation in fused fiber coupler made of two-mode fibers,” Opt. Fiber Technol. 5, 92–104 (1999).
[Crossref]

Opt. Lett. (7)

Other (1)

RSoft Design Group, Inc., Ossining, NY, USA, BeamPROP 8.2, 2010.

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Figures (10)

Fig. 1
Fig. 1 Mode-selective fiber coupler (MSFC) consisting of a single-mode fiber (SMF) and a few-mode fiber (FMF). The fundamental LP01 mode is launched into the SMF and can selectively excite HOMs in the FMF, i. e. the LP11 mode or the LP21 mode.
Fig. 2
Fig. 2 Experimentally measured transmission at a wavelength of 795 nm at the output of the SMF and FMF during the fabrication process for the non-pretapered case (a) and for the case that a pretaper length of 3.5 mm is applied on the SMF (b). The inset in (a) shows optical microscope photographs taken at a magnification of ×100 of the FMF and SMF after the etching process. The insets in (b) are showing the intensity pattern at the FMF end at the indicated extension.
Fig. 3
Fig. 3 Wavelength dependence of the fabricated MSFC. The data points were normalized to the overall transmitted power. At a wavelength of 905 nm 80 % of the injected power was transmitted in the FMF.
Fig. 4
Fig. 4 Experimentally measured transmission at a wavelength of 795 nm at the output of the SMF and FMF during the fabrication process for a pretaper length of 3 mm with a DoF of 1.98 (a) and for a pretaper length of 3.5 mm and a DoF of 1.5 (b). The insets show a photograph of the cleaved taper waist. The insets in (b) show the intensity pattern at the FMF end at the indicated extension.
Fig. 5
Fig. 5 Simulated transmission in the FMF, when light was launched into the SMF, for cladding diameters of 45 µm for both fibers. Well-fused case with a DoF of 1.7 (a) and weakly-fused case with a DoF of 1.95 (c). Pulling signature at a pretaper length of 3.5 mm in the well-fused case (b) and at a pretaper length of 5.37 mm in the weakly-fused case (d).
Fig. 6
Fig. 6 Six lowest-order SMs of the coupler structure at the beginning of the taper and the taper waist, defined by the respective propagation constant in descending order. The modes were calculated for a coupler with the same parameters used in Fig. 5(b) and at an extension of 10.6 mm.
Fig. 7
Fig. 7 (a) Evolution of the effective refractive index neff of the n-th SM along the taper position for a coupler with the same parameters used in Fig. 6 and (c) with a cladding diameter of 125 µm. (b) Second and fourth SM at a taper position between 2.8 and 7 mm. The simulated cross section is consecutively rescaled.
Fig. 8
Fig. 8 Modal excitation (a) and light propagation (b) along a coupler with an extension of 10.6 mm and a pretaper length of 3.5 mm. The light was launched into the SMF (bottom). The data points of each propagation slice were scaled to their respective maximum.
Fig. 9
Fig. 9 Evolution of the effective refractive index neff of the n-th SM along the taper position for a coupler with a DoF of 1.95 and a pretaper length of (a) 3.5 mm and (b) 5.37 mm and otherwise with the same parameters used in Fig. 6. Second and fourth SM along the propagation in the coupler for a pretaper length of 3.5 mm (c) and 5.37 mm (d). The simulated cross section is consecutively rescaled.
Fig. 10
Fig. 10 Modal excitation (a) and light propagation (b) along a coupler with an extension of 10.6 mm and a pretaper length of 5.37 mm and a DoF of 1.95.

Equations (2)

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c i = E sim ( x , y ) E i * ( x , y ) d x d y ( | E sim ( x , y ) | 2 d x d y ) . ( | E i ( x , y ) | 2 d x d y ) .
E rec ( x , y ) = i = 0 N c i E i ( x , y )

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