Abstract

A bilevel mode converter is analyzed for providing low-loss coupling between the small fundamental mode of a silicon nanowire waveguide and the larger mode of a conventional silicon-on-insulator (SOI) rib waveguide. The bilevel converter can also be used to improve the coupling efficiency between a lensed fiber and a silicon nanowire waveguide. The mode converter consists of two tapers formed at different levels. The top taper comprises a parabolic and sine taper, which is optimized to improve the mode conversion efficiency. Numerical analyses are given by using a three-dimensional semivectorial beam propagation method. The design has good tolerance against misalignment of the two masks needed for the double etch.

© 2006 IEEE

PDF Article

References

  • View by:
  • |

  1. W. Bogaerts, R. Baets, P. Dumon, V. Wiaux, S. Beckx, D. Taillaert, B. Luyssaert, J. Van Campenhout, P. Bienstman and D. Van Thourhout, "Nanophotonic waveguides in silicon-on-insulator fabricated with CMOS technology", J. Lightw. Technol., vol. 23, no. 1, pp. 401-412, Jan. 2005.
  2. D. Dai and S. He, "Analysis for characteristics of bent rib waveguides", J. Opt. Soc. Amer. A, Opt. Image Sci., vol. 21, no. 1, pp. 113-121, Jan. 2004.
  3. T. Tsuchizawa, K. Yamada, H. Fukuda, T. Watanabe, J. Takahashi, M. Takahashi, T. Shoji, E. Tamechika, S. Itabashi and H. Morita, "Microphotonics devices based on silicon microfabrication technology", IEEE J. Sel. Topics Quantum Electron., vol. 11, no. 1, pp. 232-240, Jan./Feb. 2005.
  4. V. R. Almeida, Q. Xu, C. A. Barrios and M. Lipson, "Guiding and confining light in void nanostructure", Opt. Lett., vol. 29, no. 11, pp. 1209-1211, Jun. 2004.
  5. Q. Xu, V. R. Almeida, R. R. Panepucci and M. Lipson, "Experimental demonstration of guiding and confining light in nanometer-size low-refractive-index material", Opt. Lett., vol. 29, no. 14, pp. 1626-1628, Jul. 2004.
  6. D. K. Sparcin, S. J. Spector and L. C. Kimerling, "Silicon waveguide sidewall smoothing by wet chemical oxidation", J. Lightw. Technol., vol. 23, no. 8, pp. 2455-2461, Aug. 2005.
  7. P. Dumon, W. Bogaerts, V. Wiaux, J. Wouters, S. Beckx, J. Van Campenhout, D. Taillaert, B. Luyssaert, P. Bienstman, D. Van Thourhout and R. Baets, "Low-loss SOI photonic wires and ring resonators fabricated with deep UV lithography", IEEE Photon. Technol. Lett., vol. 16, no. 5, pp. 1328-1330, May 2004.
  8. Y. A. Vlasor and S. J. Mcnab, "Losses in single-mode silicon-on-insulator strip waveguides and bends", Opt. Express, vol. 12, no. 8, pp. 1622-1631, Apr. 2004.
  9. J. H. Jang, W. Zhao, J. W. Bae, D. Selvanathan, S. L. Rommel and I. Adesida, "Direct measurement of nanoscale sidewall roughness of optical waveguides using an atomic force microscope", Appl. Phys. Lett., vol. 83, no. 20, pp. 4116-4118, Nov. 2003.
  10. F. Grillot, L. Vivien, S. Laval, D. Pascal and E. Cassan, "Size influence on the propagation loss induced by sidewall roughness in ultrasmall SOI waveguides", IEEE Photon. Technol. Lett., vol. 16, no. 7, pp. 1661-1663, Jul. 2004.
  11. W. Bogaerts, D. Taillaert and B. Luyssaert, et al. "Basic structures for photonic integrated circuits in silicon-on-insulator", Opt. Express, vol. 12, no. 8, pp. 1583-1591, Apr. 2004.
  12. K. Sasaki, F. Ohno, A. Motegi and T. Baba, "Arrayed waveguide grating of 70 × 60 µm2 size based on silicon photonic wire waveguides", Electron. Lett., vol. 41, no. 14, pp. 801-802, Jul. 2005.
  13. I. Day, I. Evans, A. Knights, F. Hopper, S. Roberts, J. Johnston, S. Day, J. Luff, H. Tsang and M. Asghari, "Tapered silicon waveguides for low insertion loss highly-efficient high-speed electronic variable optical attenuators", in Proc. OFC, Atlanta, GA, Mar. 2003, pp. 249-251.
  14. D. X. Dai, J. J. He and S. L He, "Elimination of multimode effects in a silicon-on-insulator etched diffraction grating demultiplexer with bi-level taper structure", IEEE J. Sel. Topics Quantum Electron., vol. 11, no. 2, pp. 439-443, Mar./Apr. 2005.
  15. D. Taillaert, W. Bogaerts, P. Bienstman, T. F. Krauss, P. V. Daele, I. Moerman, S. Verstuyft, K. D. Mesel and R. Baets, "An out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fibers", IEEE J. Quantum Electron., vol. 38, no. 7, pp. 949-955, Jul. 2002.
  16. T. Shoji, T. Tsuchizawa, T. Watanabe, K. Yamada and H. Morita, "Low loss mode size converter from 0.3 µm square silicon wire waveguides to single-mode fibers", Electron. Lett., vol. 38, no. 25, pp. 1669-1670, Dec. 2002.
  17. V. R. Almeida, R. R. Panepucci and M. Lipson, "Nanotaper for compact mode conversion", Opt. Lett., vol. 28, no. 15, pp. 1302-1304, Aug. 2003.
  18. K. K. Lee, D. R. Lim, D. Pan, C. Hoepfner, W.-Y. Oh, K. Wada, L. C. Kimerling, K. P. Yap and M. T. Doan, "Mode transformer for miniaturized optical circuits", Opt. Lett., vol. 30, no. 5, pp. 498-500, Mar. 2005.
  19. G. Z. Masanovic, G. T. Reed, W. Headley and B. Timotijevic, "A high efficiency input/output coupler for small silicon photonic devices", Opt. Express, vol. 13, no. 19, pp. 7374-7379, Sep. 2005.
  20. R. N. Thurston, E. Kapon and A. Shahar, "Two-dimensional control of mode size in optical channel waveguide by lateral channel tapering", Opt. Lett., vol. 16, no. 5, pp. 306-308, Mar. 1991.
  21. F. Payne, "Semiconductor optical waveguide device", U.S. Patent 6 853 775, Feb. 8, 2005.
  22. P.-L. Liu and B.-J. Li, "Semivectorial beam-propagation method for analyzing polarized modes of rib waveguides", IEEE J. Quantum Electron., vol. 28, no. 4, pp. 778-782, Apr. 1992.
  23. W. P. Huang, C. I. Xu, W. Lui and K. Yokoyama, "The perfectly matched layer boundary condition for modal analysis of optical waveguides: Leaky mode calculations", IEEE Photon. Technol. Lett., vol. 8, no. 5, pp. 652-654, May 1996.

Other (23)

W. Bogaerts, R. Baets, P. Dumon, V. Wiaux, S. Beckx, D. Taillaert, B. Luyssaert, J. Van Campenhout, P. Bienstman and D. Van Thourhout, "Nanophotonic waveguides in silicon-on-insulator fabricated with CMOS technology", J. Lightw. Technol., vol. 23, no. 1, pp. 401-412, Jan. 2005.

D. Dai and S. He, "Analysis for characteristics of bent rib waveguides", J. Opt. Soc. Amer. A, Opt. Image Sci., vol. 21, no. 1, pp. 113-121, Jan. 2004.

T. Tsuchizawa, K. Yamada, H. Fukuda, T. Watanabe, J. Takahashi, M. Takahashi, T. Shoji, E. Tamechika, S. Itabashi and H. Morita, "Microphotonics devices based on silicon microfabrication technology", IEEE J. Sel. Topics Quantum Electron., vol. 11, no. 1, pp. 232-240, Jan./Feb. 2005.

V. R. Almeida, Q. Xu, C. A. Barrios and M. Lipson, "Guiding and confining light in void nanostructure", Opt. Lett., vol. 29, no. 11, pp. 1209-1211, Jun. 2004.

Q. Xu, V. R. Almeida, R. R. Panepucci and M. Lipson, "Experimental demonstration of guiding and confining light in nanometer-size low-refractive-index material", Opt. Lett., vol. 29, no. 14, pp. 1626-1628, Jul. 2004.

D. K. Sparcin, S. J. Spector and L. C. Kimerling, "Silicon waveguide sidewall smoothing by wet chemical oxidation", J. Lightw. Technol., vol. 23, no. 8, pp. 2455-2461, Aug. 2005.

P. Dumon, W. Bogaerts, V. Wiaux, J. Wouters, S. Beckx, J. Van Campenhout, D. Taillaert, B. Luyssaert, P. Bienstman, D. Van Thourhout and R. Baets, "Low-loss SOI photonic wires and ring resonators fabricated with deep UV lithography", IEEE Photon. Technol. Lett., vol. 16, no. 5, pp. 1328-1330, May 2004.

Y. A. Vlasor and S. J. Mcnab, "Losses in single-mode silicon-on-insulator strip waveguides and bends", Opt. Express, vol. 12, no. 8, pp. 1622-1631, Apr. 2004.

J. H. Jang, W. Zhao, J. W. Bae, D. Selvanathan, S. L. Rommel and I. Adesida, "Direct measurement of nanoscale sidewall roughness of optical waveguides using an atomic force microscope", Appl. Phys. Lett., vol. 83, no. 20, pp. 4116-4118, Nov. 2003.

F. Grillot, L. Vivien, S. Laval, D. Pascal and E. Cassan, "Size influence on the propagation loss induced by sidewall roughness in ultrasmall SOI waveguides", IEEE Photon. Technol. Lett., vol. 16, no. 7, pp. 1661-1663, Jul. 2004.

W. Bogaerts, D. Taillaert and B. Luyssaert, et al. "Basic structures for photonic integrated circuits in silicon-on-insulator", Opt. Express, vol. 12, no. 8, pp. 1583-1591, Apr. 2004.

K. Sasaki, F. Ohno, A. Motegi and T. Baba, "Arrayed waveguide grating of 70 × 60 µm2 size based on silicon photonic wire waveguides", Electron. Lett., vol. 41, no. 14, pp. 801-802, Jul. 2005.

I. Day, I. Evans, A. Knights, F. Hopper, S. Roberts, J. Johnston, S. Day, J. Luff, H. Tsang and M. Asghari, "Tapered silicon waveguides for low insertion loss highly-efficient high-speed electronic variable optical attenuators", in Proc. OFC, Atlanta, GA, Mar. 2003, pp. 249-251.

D. X. Dai, J. J. He and S. L He, "Elimination of multimode effects in a silicon-on-insulator etched diffraction grating demultiplexer with bi-level taper structure", IEEE J. Sel. Topics Quantum Electron., vol. 11, no. 2, pp. 439-443, Mar./Apr. 2005.

D. Taillaert, W. Bogaerts, P. Bienstman, T. F. Krauss, P. V. Daele, I. Moerman, S. Verstuyft, K. D. Mesel and R. Baets, "An out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fibers", IEEE J. Quantum Electron., vol. 38, no. 7, pp. 949-955, Jul. 2002.

T. Shoji, T. Tsuchizawa, T. Watanabe, K. Yamada and H. Morita, "Low loss mode size converter from 0.3 µm square silicon wire waveguides to single-mode fibers", Electron. Lett., vol. 38, no. 25, pp. 1669-1670, Dec. 2002.

V. R. Almeida, R. R. Panepucci and M. Lipson, "Nanotaper for compact mode conversion", Opt. Lett., vol. 28, no. 15, pp. 1302-1304, Aug. 2003.

K. K. Lee, D. R. Lim, D. Pan, C. Hoepfner, W.-Y. Oh, K. Wada, L. C. Kimerling, K. P. Yap and M. T. Doan, "Mode transformer for miniaturized optical circuits", Opt. Lett., vol. 30, no. 5, pp. 498-500, Mar. 2005.

G. Z. Masanovic, G. T. Reed, W. Headley and B. Timotijevic, "A high efficiency input/output coupler for small silicon photonic devices", Opt. Express, vol. 13, no. 19, pp. 7374-7379, Sep. 2005.

R. N. Thurston, E. Kapon and A. Shahar, "Two-dimensional control of mode size in optical channel waveguide by lateral channel tapering", Opt. Lett., vol. 16, no. 5, pp. 306-308, Mar. 1991.

F. Payne, "Semiconductor optical waveguide device", U.S. Patent 6 853 775, Feb. 8, 2005.

P.-L. Liu and B.-J. Li, "Semivectorial beam-propagation method for analyzing polarized modes of rib waveguides", IEEE J. Quantum Electron., vol. 28, no. 4, pp. 778-782, Apr. 1992.

W. P. Huang, C. I. Xu, W. Lui and K. Yokoyama, "The perfectly matched layer boundary condition for modal analysis of optical waveguides: Leaky mode calculations", IEEE Photon. Technol. Lett., vol. 8, no. 5, pp. 652-654, May 1996.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.