[1] [1] R. J. Campbell, R. Kashyap. The properties and applications of photosensitive germanosilicate fiber. Inter. J. Optoelectronics, 1994, 9(1):33～57

[2] [2] G. P. Agrawal, S. Radic. Phase-shifted fiber Bragg gratings and their application for wavelength demultiplexer. IEEE Photon. Technol. Lett., 1994, 6(8):995～997

[3] [3] F. Ouellette. Dispersion cancellation using linearly chirped Bragg grating filters in optical waveguides. Opt. Lett., 1987, 12(10):847～849

[4] [4] F. Bilodeau, K. O. Hill, B. Malo et al.. High-return-loss narrowband all-fiber bandpass Bragg transmission filter. IEEE Photon. Technol. Lett., 1994, 6(1):80～82

[5] [5] L. Zhang, K. Sugden, J. A. R. Williams et al.. Postfabrication exposure of gap-type bandpass filters in broadly chirped fiber gratings. Opt. Lett., 1995, 20(18):1927～1929