Abstract

By means of coupled-mode theory, an optical waveguide coupler consisting of two parallel identical waveguides, each of which contains a uniform long-period grating was analyzed. The authors show that light can be coupled effectively between the two waveguides through the gratings at specific wavelengths (the resonance wavelengths) in the absence of evanescent-field coupling. The conditions for achieving 100% coupling efficiency at the resonance wavelength under various situations are highlighted and the effects of the grating parameters on the transmission spectra of the coupler are illustrated with examples. Practical waveguide designs for the realization of the coupler are also presented. The long-period waveguide-grating (LPWG) coupler is a versatile waveguide structure and should find potential applications in optical filtering, add/drop multiplexing, and optical switching.

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  1. A. M. Vengsarkar, P. J. Lemaire, J. B. Judkins, V. Bhatia, T. Erdogan and J. E. Sipe, "Long-period fiber gratings as band-rejection filters", J. Lightw. Technol., vol. 14, no. 1, pp. 58-65, Jan. 1996.
  2. X. J. Gu, "Wavelength-division multiplexing isolation fiber filter and light source using cascaded long-period fiber gratings", Opt. Lett., vol. 23, no. 7, pp. 509-510, Apr. 1998.
  3. A. M. Vengsarkar, J. R. Pedrazzani, J. B. Judkins, P. J. Lemaire, N. S. Bergano and C. R. Davidson, "Long-period fiber-grating-based gain equalizer", Opt. Lett., vol. 21, no. 5, pp. 336-338, Mar. 1996.
  4. P. F. Wysocki, J. B. Judkins, R. P. Espindola, M. Andrejco and A. M. Vengsarkar, "Broad-band erbium-doped fiber amplifier flattened beyond 40 nm using long-period grating filter", IEEE Photon. Technol. Lett., vol. 9, no. 10, pp. 1343-1345, Oct. 1997.
  5. M. K. Pandit, K. S. Chiang, Z. H. Chen and S. P. Li, "Tunable long-period fiber gratings for EDFA gain and ASE equalization", Microw. Opt. Technol. Lett., vol. 25, no. 3, pp. 181-184, May 2000.
  6. D. B. Stegall and T. Erdogan, "Dispersion control with use of long-period fiber gratings", J. Opt. Soc. Amer. A, Opt. Image Sci., vol. 17, no. 2, pp. 304-312, Feb. 2000.
  7. V. Bhatia, D. Campbell, R. O. Claus and A. M. Vengsarkar, "Simultaneous strain and temperature measurement with long-period gratings", Opt. Lett., vol. 22, no. 9, pp. 648-650, May 1997.
  8. H. J. Patrick, C. C. Chang and S. T. Vohra, "Long period fibre gratings for structural bend sensing", Electron. Lett., vol. 34, no. 18, pp. 1773-1775, Sep. 1998.
  9. V. Grubsky and J. Feinberg, "Long-period fiber gratings with variable coupling for real-time sensing applications", Opt. Lett., vol. 25, no. 4, pp. 203-205, Feb. 2000.
  10. M. N. Ng, Z. Chen and K. S. Chiang, "Temperature compensation of long-period fiber grating for refractive-index sensing with bending effect", IEEE Photon. Technol. Lett., vol. 14, no. 3, pp. 361-363, Mar. 2002.
  11. K. S. Chiang, Y. Liu, M. N. Ng and S. Li, "Coupling between two parallel long-period fibre gratings", Electron. Lett., vol. 36, no. 16, pp. 1408-1409, Aug. 2000.
  12. K. S. Chiang, M. N. Ng, Y. Liu and S. Li, "Evanescent-field coupling between two parallel long-period fiber gratings", in Proc. IEEE Lasers and Electro-Optics Society Conf., Rio Grande, PR, 2000, pp. 836-837.
  13. V. Grubsky, D. S. Starodubov and J. Feinberg, "Wavelength-selective coupler and add-drop multiplexer using long-period fiber gratings", in Tech. Dig., Optical Fiber Communication Conf., vol. 4, Baltimore, MD, 2000, pp. 28-30.
  14. K. S. Chiang, F. Y. M. Chan and M. N. Ng, "Analysis of two parallel long-period fiber gratings", J. Lightw. Technol., vol. 22, no. 5, pp. 1358-1366, May 2004.
  15. V. Rastogi and K. S. Chiang, "Long-period gratings in planar optical waveguides", Appl. Opt., vol. 41, no. 30, pp. 6351-6355, Oct. 2002.
  16. Q. Liu, K. S. Chiang and V. Rastogi, "Analysis of corrugated long-period waveguide gratings and their polarization dependence", J. Lightw. Technol., vol. 21, no. 12, pp. 3399-3405, Dec. 2003.
  17. K. S. Chiang, K. P. Lor, C. K. Chow, H. P. Chan, V. Rastogi and Y. M. Chu, "Widely tunable long-period gratings fabricated in polymer-clad ion-exchanged glass waveguides", IEEE Photon. Technol. Lett., vol. 15, no. 8, pp. 1094-1096, Aug. 2003.
  18. K. S. Chiang, C. K. Chow, H. P. Chan, Q. Liu and K. P. Lor, "Widely tunable polymer long-period waveguide grating with polarization-insensitive resonance wavelength", Electron. Lett., vol. 40, no. 7, pp. 422-424, Apr. 2004.
  19. Y. M. Chu, Q. Liu and K. S. Chiang, "Control of temperature sensitivity of long-period waveguide grating by etching of cladding", in Proc. 9th Optoelectronics and Communications Conf. (OECC), Yokohama, Japan, 2004, pp. 920-921.
  20. M.-S. Kwon and S.-Y. Shin, "Characteristics of polymer waveguide notch filters using thermooptic long-period gratings", IEEE J. Sel. Topics Quantum Electron., vol. 11, no. 1, pp. 190-196, Jan./Feb. 2005.
  21. M.-S. Kwon and S.-Y. Shin, "Polymer waveguide notch filter using two stacked thermooptic long-period gratings", IEEE Photon. Technol. Lett., vol. 17, no. 4, pp. 792-794, Apr. 2005.
  22. K. P. Lor, Q. Liu and K. S. Chiang, "UV-written long-period gratings on polymer waveguides", IEEE Photon. Technol. Lett., vol. 17, no. 3, pp. 594-596, Mar. 2005.
  23. G. Griffel, M. Itzkovich and A. A. Hardy, "Coupled mode formulation for directional couplers with longitudinal perturbation", IEEE J. Quantum Electron., vol. 27, no. 4, pp. 985-994, Apr. 1991.
  24. W. P. Huang, B. E. Little and S. K. Chaudhuri, "A new approach to grating-assisted couplers", J. Lightw. Technol., vol. 9, no. 6, pp. 721-727, Jun. 1991.
  25. A. S. Sudbo, "Numerically stable formulation of the transverse resonance method for vector mode-field calculations in dielectric waveguides", IEEE Photon. Technol. Lett., vol. 5, no. 3, pp. 342-344, Mar. 1993.
  26. M. Svalgaard, "Ultraviolet light induced refractive index structures in germanosilica", Ph.D. dissertation, Mikroelektronik Centret, Technical Univ. Denmark, Lyngby, Denmark, 1997.
  27. M. R. Poulsen, P. I. Borel, J. Fage-Pedersen, J. Hübner, M. Kristensen, J. H. Povlsen, K. Rottwitt, M. Svalgaard and W. Svendsen, "Advances in silica-based integrated optics", Opt. Eng., vol. 42, no. 10, pp. 2821-2834, Oct. 2003.

Other (27)

A. M. Vengsarkar, P. J. Lemaire, J. B. Judkins, V. Bhatia, T. Erdogan and J. E. Sipe, "Long-period fiber gratings as band-rejection filters", J. Lightw. Technol., vol. 14, no. 1, pp. 58-65, Jan. 1996.

X. J. Gu, "Wavelength-division multiplexing isolation fiber filter and light source using cascaded long-period fiber gratings", Opt. Lett., vol. 23, no. 7, pp. 509-510, Apr. 1998.

A. M. Vengsarkar, J. R. Pedrazzani, J. B. Judkins, P. J. Lemaire, N. S. Bergano and C. R. Davidson, "Long-period fiber-grating-based gain equalizer", Opt. Lett., vol. 21, no. 5, pp. 336-338, Mar. 1996.

P. F. Wysocki, J. B. Judkins, R. P. Espindola, M. Andrejco and A. M. Vengsarkar, "Broad-band erbium-doped fiber amplifier flattened beyond 40 nm using long-period grating filter", IEEE Photon. Technol. Lett., vol. 9, no. 10, pp. 1343-1345, Oct. 1997.

M. K. Pandit, K. S. Chiang, Z. H. Chen and S. P. Li, "Tunable long-period fiber gratings for EDFA gain and ASE equalization", Microw. Opt. Technol. Lett., vol. 25, no. 3, pp. 181-184, May 2000.

D. B. Stegall and T. Erdogan, "Dispersion control with use of long-period fiber gratings", J. Opt. Soc. Amer. A, Opt. Image Sci., vol. 17, no. 2, pp. 304-312, Feb. 2000.

V. Bhatia, D. Campbell, R. O. Claus and A. M. Vengsarkar, "Simultaneous strain and temperature measurement with long-period gratings", Opt. Lett., vol. 22, no. 9, pp. 648-650, May 1997.

H. J. Patrick, C. C. Chang and S. T. Vohra, "Long period fibre gratings for structural bend sensing", Electron. Lett., vol. 34, no. 18, pp. 1773-1775, Sep. 1998.

V. Grubsky and J. Feinberg, "Long-period fiber gratings with variable coupling for real-time sensing applications", Opt. Lett., vol. 25, no. 4, pp. 203-205, Feb. 2000.

M. N. Ng, Z. Chen and K. S. Chiang, "Temperature compensation of long-period fiber grating for refractive-index sensing with bending effect", IEEE Photon. Technol. Lett., vol. 14, no. 3, pp. 361-363, Mar. 2002.

K. S. Chiang, Y. Liu, M. N. Ng and S. Li, "Coupling between two parallel long-period fibre gratings", Electron. Lett., vol. 36, no. 16, pp. 1408-1409, Aug. 2000.

K. S. Chiang, M. N. Ng, Y. Liu and S. Li, "Evanescent-field coupling between two parallel long-period fiber gratings", in Proc. IEEE Lasers and Electro-Optics Society Conf., Rio Grande, PR, 2000, pp. 836-837.

V. Grubsky, D. S. Starodubov and J. Feinberg, "Wavelength-selective coupler and add-drop multiplexer using long-period fiber gratings", in Tech. Dig., Optical Fiber Communication Conf., vol. 4, Baltimore, MD, 2000, pp. 28-30.

K. S. Chiang, F. Y. M. Chan and M. N. Ng, "Analysis of two parallel long-period fiber gratings", J. Lightw. Technol., vol. 22, no. 5, pp. 1358-1366, May 2004.

V. Rastogi and K. S. Chiang, "Long-period gratings in planar optical waveguides", Appl. Opt., vol. 41, no. 30, pp. 6351-6355, Oct. 2002.

Q. Liu, K. S. Chiang and V. Rastogi, "Analysis of corrugated long-period waveguide gratings and their polarization dependence", J. Lightw. Technol., vol. 21, no. 12, pp. 3399-3405, Dec. 2003.

K. S. Chiang, K. P. Lor, C. K. Chow, H. P. Chan, V. Rastogi and Y. M. Chu, "Widely tunable long-period gratings fabricated in polymer-clad ion-exchanged glass waveguides", IEEE Photon. Technol. Lett., vol. 15, no. 8, pp. 1094-1096, Aug. 2003.

K. S. Chiang, C. K. Chow, H. P. Chan, Q. Liu and K. P. Lor, "Widely tunable polymer long-period waveguide grating with polarization-insensitive resonance wavelength", Electron. Lett., vol. 40, no. 7, pp. 422-424, Apr. 2004.

Y. M. Chu, Q. Liu and K. S. Chiang, "Control of temperature sensitivity of long-period waveguide grating by etching of cladding", in Proc. 9th Optoelectronics and Communications Conf. (OECC), Yokohama, Japan, 2004, pp. 920-921.

M.-S. Kwon and S.-Y. Shin, "Characteristics of polymer waveguide notch filters using thermooptic long-period gratings", IEEE J. Sel. Topics Quantum Electron., vol. 11, no. 1, pp. 190-196, Jan./Feb. 2005.

M.-S. Kwon and S.-Y. Shin, "Polymer waveguide notch filter using two stacked thermooptic long-period gratings", IEEE Photon. Technol. Lett., vol. 17, no. 4, pp. 792-794, Apr. 2005.

K. P. Lor, Q. Liu and K. S. Chiang, "UV-written long-period gratings on polymer waveguides", IEEE Photon. Technol. Lett., vol. 17, no. 3, pp. 594-596, Mar. 2005.

G. Griffel, M. Itzkovich and A. A. Hardy, "Coupled mode formulation for directional couplers with longitudinal perturbation", IEEE J. Quantum Electron., vol. 27, no. 4, pp. 985-994, Apr. 1991.

W. P. Huang, B. E. Little and S. K. Chaudhuri, "A new approach to grating-assisted couplers", J. Lightw. Technol., vol. 9, no. 6, pp. 721-727, Jun. 1991.

A. S. Sudbo, "Numerically stable formulation of the transverse resonance method for vector mode-field calculations in dielectric waveguides", IEEE Photon. Technol. Lett., vol. 5, no. 3, pp. 342-344, Mar. 1993.

M. Svalgaard, "Ultraviolet light induced refractive index structures in germanosilica", Ph.D. dissertation, Mikroelektronik Centret, Technical Univ. Denmark, Lyngby, Denmark, 1997.

M. R. Poulsen, P. I. Borel, J. Fage-Pedersen, J. Hübner, M. Kristensen, J. H. Povlsen, K. Rottwitt, M. Svalgaard and W. Svendsen, "Advances in silica-based integrated optics", Opt. Eng., vol. 42, no. 10, pp. 2821-2834, Oct. 2003.

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