Abstract
We analyze the effects of average index variation on the transmission characteristics of an index-apodized long-period fiber grating (LPFG) by the transfer matrix method and study how these effects depend on the grating length, the grating profile, the modal dispersion factor, and the duty cycle of the index modulation. Apart from shifting the resonance wavelength and modifying the rejection band, average index variation can give rise to significant side lobes that may appear on the short-wavelength or long-wavelength side of the rejection band, depending on the signs of the average index change and the modal dispersion factor. Our results provide general guidance for the writing of LPFGs for the minimization of side lobes. Our analysis compares well with published experimental results and should be useful for the design and fabrication of LPFGs.
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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,” Journal of Lightwave Technology, vol. 14, no. 1, pp. 58–65, 1996.
K. S. Chiang and Q. Liu, “Long-period grating devices for application in optical communication,” in Proceedings of 5th International Conference on Optical Communications and Networks and 2nd International Symposium on Advances and Trends in Fiber Optics Applications (ICOCN/ATFO), Chengdu, China, September, pp. 128–133, 2006.
R. Slavík, Y. Park, M. Kulishov, R. Morandotti, and J. Azaña, “Ultrafast all-optical differentiators,” Optics Express, vol. 14, no. 22, pp. 10699–10707, 2006.
S. W. James and R. P. Tatam, “Optical fibre long-period grating sensors: characteristics and application,” Measurement Science & Technology, vol. 14, no. 5, pp. R49–R61, 2003.
D. nodop, C. Jauregui, F. Jansen, J. Limpert, and A. Tünnermann, “Suppression of stimulated Raman scattering employing long period gratings in double-clad fiber amplifiers,” Optics Letters, vol. 35, no. 17, pp. 2982–2984, 2010.
F. Y. M. Chan and K. S. Chiang, “Analysis of apodized phase-shifted long-period fiber gratings,” Optics Communications, vol. 244, no. 1–6, pp. 233–243, 2005.
Y. Gu, K. S. Chiang, and Y. J. Rao, “Writing of apodized phase-shifted long-period fiber gratings with a computer-controlled CO2 laser,” IEEE Photonics Technology Letters, vol. 21, no. 10, pp. 657–659, 2009.
X. Shu, K. Sugden, and I. Bennion, “Apodisation of photo-induced waveguide gratings using double-exposure with complementary duty cycles,” Optics Express, vol. 16, no. 3, pp. 2221–2225, 2008.
V. Mizrahi and J. E. Sipe, “Optical properties of photosensitive fiber phase gratings,” Journal of Lightwave Technology, vol. 11, no. 10, pp. 1513–1517, 1993.
H. Kogelnik, “Filter response of nonuniform almost-periodic structures,” The Bell System Technical Journal, vol. 55, no. 1, pp. 109–126, 1976.
J. E. Sipe, L. Poladian, and C. M. De Sterke, Propagation through nonuniform grating structures,” Journal of the Optical Society of America A: Optic s and Image Science, vol. 11, no. 4, pp. 1307–1320, 1994.
A. W. Snyder and J. D. Love. Optical Waveguide Theory. London: Chapman and Hall, 1983.
T. W. MacDougall, S. Pilevar, C. W. Haggans, and M. A. Jackson, “Generalized expression for the growth of long period gratings,” IEEE Photonics Technology Letters, vol. 10, no. 10, pp. 1449–1451, 2002.
M. Yamada and K. Sakuda, “Analysis of almost-periodic distributed feedback slab waveguides via a fundamental matrix approach,” Applied Optics, vol. 26, no. 16, pp. 3474–3478, 1987.
H. Ke, K. S. Chiang, and J. H. Peng, “Analysis of phase-shifted long-period fiber gratings,” IEEE Photonics Technology Letters, vol. 10, no. 11, pp. 1596–1598, 1998.
M. Monerie, “Propagation in doubly clad single-mode fibers,” IEEE Journal of Quantum Electronics, vol. 18, no. 4, pp. 535–542, 1982.
T. Erdogan, “Fiber grating spectra,” Journal of Lightwave Technology, vol. 15, no. 8, pp. 1277–1294, 1997.
X. Shu, L. Zhang, and I. Bennion, “Sensitivity characteristics of long-period fiber gratings,” Journal of Lightwave Technology, vol. 20, no. 2, pp. 255–266, 2002.
D. D. Davis, T. K. Gaylord, E. N. Glytsis, S. G. Kosinski, S. C. Mettler, and A. M. Vengsarkar, “Long-period fibre grating fabrication with focused CO2 laser beams,” Electronics Letters, vol. 34, no. 3, pp. 302–303, 1998.
Y. Kondo, K. nouchi, T. Mitsuyu, M. Watanabe, P. G. Kazansky, and K. Hirao, “Fabrication of long-period fiber gratings by focused irradiation of infrared femtosecond laser pulses,” Optics Letters, vol. 24, no. 10, pp. 646–648, 1999.
V. Grubsky, A. Skorucak, D. S. Starodubov, and J. Feinberg, “Fabrication of spectrally-clean, long-period grating filters,” in Technical Digest of Optical Fiber Communication Conference, San Diego, Feb. 21–26, pp. 174–176, 1999.
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Gu, Y., Chiang, K.S. Effects of average index variation in apodized long-period fiber gratings. Photonic Sens 3, 102–111 (2013). https://doi.org/10.1007/s13320-013-0074-y
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DOI: https://doi.org/10.1007/s13320-013-0074-y