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Electrically Controllable Fiber Bragg Gratings with Liquid Crystal Cladding

  • Baek Seungin (School of Electrical Engineering, Seoul National University) ;
  • Roh Sookyoung (School of Electrical Engineering, Seoul National University) ;
  • Na Jun-Hee (School of Electrical Engineering, Seoul National University) ;
  • Kwon Jaejoong (School of Electrical Engineering, Seoul National University) ;
  • Yoon Ilyong (School of Electrical Engineering, Seoul National University) ;
  • Chung Seunghwan (School of Electrical Engineering, Seoul National University) ;
  • Jeong Cherlhyun (School of Electrical Engineering, Seoul National University) ;
  • Lee Sin-Doo (School of Electrical Engineering, Seoul National University) ;
  • Lee Byoungho (Optoelectronics Research Center, University of Southampton) ;
  • Jeong Yoonchan (Optoelectronics Research Centre, University of Southampton)
  • 투고 : 2005.09.05
  • 발행 : 2005.09.01

초록

An electrically controllable fiber Bragg grating inscribed in a hydrogen-loaded standard single-mode fiber with liquid-crystal cladding is presented. Control of the optic axis of liquid crystals by means of external electric fields results in the change of reflectivity and Bragg wavelength of the grating. The increase of surrounding refractive index of a fiber makes effective refractive index of a propagation mode higher, which results in high field confinement and longer Bragg wavelength. The reduction of the fiber diameter by chemical etching process improves the long-range ordering of liquid-crystal molecules and reduces controlling voltage. The tunable ranges of reflectivity and Bragg wavelength of the liquid crystal-cladding fiber Bragg grating were $\~4.6dB\;and\;\~0.3nm$, respectively.

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참고문헌

  1. K. O. Hill, and G. Meltz, 'Fiber Bragg grating technology fundamentals and overview,' J. Lightwave Technol., vol. 15, pp. 1263-1276, 1997 https://doi.org/10.1109/50.618320
  2. 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. Lightwave Technol., vol. 14, pp. 58-65, 1996 https://doi.org/10.1109/50.476137
  3. B. Lee, 'Review of the present status of optical fiber sensors,' Opt. Fiber Technol., vol. 9, pp. 57-79, 2003 https://doi.org/10.1016/S1068-5200(02)00527-8
  4. S. Baek, Y. Jeong, and B. Lee, 'Characteristics of short-period blazed fiber Bragg gratings for macro-bending sensors,' Appl. Opt., vol. 41, pp. 631-636, 2002 https://doi.org/10.1364/AO.41.000631
  5. J. Kim, and B. Lee, 'Bidirectional wavelength add-drop multiplexer using multiport optical circulators and fiber Bragg gratings,' IEEE Photon. Technol. Lett., vol. 12, pp. 561-563, 2000 https://doi.org/10.1109/68.841286
  6. D. M. Costantini, C. A. P. Muller, S. A. Vasiliev, H. G. Limberger, and R. P. Salathe, 'Tunable loss filter based on metal-coated long-period fiber grating,' IEEE Photon. Technol. Lett., vol. 11, pp. 1458-1460, 1999 https://doi.org/10.1109/68.803078
  7. J. H. Lee, Y. M. Chang, Y.-G. Han, S.-H. Kim, and S. B. Lee, 'Wavelength and repetition rate tunable optical pulse source using a chirped fiber Bragg grating and a nonlinear optical loop mirror,' IEEE Photon. Technol. Lett., vol. 17, pp. 34-36, 2005 https://doi.org/10.1109/LPT.2004.838289
  8. J. Kwon, and B. Lee, 'Dispersion tuning of a chirped fiber Bragg grating using a multisectional bending structure,' IEEE Photon. Technol. Lett., vol. 17, pp. 408-410, 2005 https://doi.org/10.1109/LPT.2004.839379
  9. D.-W. Huang, W.-F. Liu, C.-W. Wu, and C. C. Yang, 'Reflectivity-tunable fiber Bragg grating reflectors,' IEEE Photon. Technol. Lett., vol. 12, pp. 176-178, 2000 https://doi.org/10.1109/68.823508
  10. A. Iocco, H. G. Limberger, R. P. Salathe, L. A. Everall, K. E. Chisholm, J. A. R. Williams, and I. Bennion, 'Bragg grating fast tunable filter for wavelength division multiplexing,' J. Lightwave Technol., vol. 17, pp. 1217-1221, 1999 https://doi.org/10.1109/50.774258
  11. O. Duhem, J. F. Henninot, M. Warenghem, M. Douay, and L. Rivoallan, 'Long period fiber gratings modulation by liquid crystal cladding,' in Proc. 6th lEE Conf. on Telecommunications, pp. 195-197, 1998
  12. Y. Jeong, H.-R. Kim, S. Baek, Y. Kim, S.-D. Lee, and B. Lee, 'Polarization-isolated electrical modulation of an etched long-period fiber grating with an outer liquid-crystal cladding,' Opt. Eng., vol. 42, pp. 964-968, 2003 https://doi.org/10.1117/1.1555011
  13. T. Erdogan, 'Fiber grating spectra,' J. Lightwave Technol., vol. 15, pp. 1277-1294, 1997 https://doi.org/10.1109/50.618322
  14. Y. Jeong, and B. Lee, 'Long-period fiber grating analysis using generalized NxN coupled-mode theory by sectionwise discretization,' J. Opt. Soc. Korea, vol. 3, pp. 55-63, 1999 https://doi.org/10.3807/JOSK.1999.3.2.055
  15. I.-C. Khoo, Liquid Crystals, Wiley, New York, 1994
  16. S.-T. Wu and U. Efron, 'Optical property of thin nematic liquid crystal cells,' Appl. Phys. Lett., vol. 48, pp. 624-626, 1986 https://doi.org/10.1063/1.96724
  17. E. P. Raynes, 'The chemistry and physics of thermotropic liquid crystals,' in Electro-optic and Photorefractive Materials, P. Gunter, Ed., Springer Proceedings in Physics, vol. 18, pp. 80-89, Springer, Berlin, 1987 https://doi.org/10.1007/978-3-642-71907-3_7
  18. M. Monerie, 'Propagation in doubly clad single-mode fibers,' IEEE J. Quantum Eleciron., vol. QE-18, pp. 535-542, 1982 https://doi.org/10.1109/JQE.1982.1071586
  19. S. Kawakami, and S. Nishida, 'Characteristics of a doubly clad optical fiber with a low-index inner cladding,' IEEE J. Quantum Eleciron., vol. QE-10, pp. 879-887, 1974 https://doi.org/10.1109/JQE.1974.1068118
  20. A. W. Snyder, and W. R. Young, 'Modes of optical waveguides,' J. Opt. Soc. Amer., vol. 68, pp. 297-309, 1978 https://doi.org/10.1364/JOSA.68.000297
  21. S.-P. Ma and S.-M. Tseng, 'High-performance sidepolished fibers and applications as liquid crystal clad fiber polarizers,' J. Lightwave Technol., vol. 15, pp. 1554-1558, 1997 https://doi.org/10.1109/50.618389