[1] [1] Yamada M,Kanamori T,Terunuma Y,et al. Fluoride-based erbium-doped fiber amplifier with inherently flat gain spectrum. IEEE Photon Technol Lett, 1996,8 (7) :882～884

[2] [2] Yoshida S,Kuwano S,Iwashita K. Gain-flattened EDFA with high Alconcentration for multistage repeatered WDM transmission systems. Electron Lett, 1995,31 (20): 1765～1767

[4] [4] Liaw S K, Ho K P, Chi S. Dynamic Power-equalized EDFA module based on strain tunable fiber Bragg gratings. IEEE Photon Technol Lett, 1999,11 (7) :797 ～ 799

[5] [5] Chi Hao,Zhao Huandong,Zeng Qingji,et al. Erbium doped fiber amplifier using fiber Bragg grating as gain equalizer.Acta Photonica Sinica,2002,31 (10): 1248 ～ 1251

[8] [8] Wysocki P F,Judkins J B,Espindola R P,et al. Broad-band erbium-doped fiber amplifier flattened beyond 40nm using long-period grating filter. IEEE Photon Technol Lett , 1997,9(10) :1343 ～ 1345

[11] [11] Yun S K,Lee B W,Kim H K,et al. Dynamic erbium-doped fiber amplifier based on active gain flattening with fiber acoustooptic tunable filter. IEEE Photon Technol Lett,1999,11(10) :1229 ～ 1231

[12] [12] Yamada M, Mori A, Kobayashi K, et al. Gain-flattened tellurite-based EDFA with a flat amplification bandwidth of 76 nm. IEEE Photon Techol Lett,1998,10(9) :244～246

[13] [13] Montemezzani G, Zgonik M. Light diffraction at mixed phase and absorption gratings in anisotropic media for arbitrary geometries. Physical Review E, 1997,55 (1): 1035～1047

[14] [14] Kazuyou Mizuno, Yasuhiro Nishi, You Mimura, et al.Development of etalon-type gain-flatting filter. Furukawa Review, 2000, (19) :53～58

[17] [17] Wu B G,West J L,Doane J W. Abgular discrimination of light transmission through polmer-dispersed liquid crystal films. J Appl Phys, 1987,62 (9): 3925 ～ 3931

[18] [18] Sutherland R L, Tondiglia V P, Natarajan L V, et al.Electrically switchable volume gratings in polmer-dispersed liquid crystals. Appl Phys Lett, 1994,64 (9): 1074 ～ 1076