[1] [1] GILES C R,DESURVIRE E.Modeling erbium-doped fiber amplifiers[J].J Lightwave Technol,1991,9(3):271-283.

[2] [2] RAO Yun-jiang,ZHU Tao,RAN Zeng-ling,et al.Novel long-period fiber gratings written by high-frequency CO2 laser pulses and applications in optical fiber communication[J].Optics Commun,2004,229(1):209-221.

[3] [3] FECED R,ALEGRIA C,ZERVAS M N,et al.Acoustooptic attenuation filters based on tapered optical fibers[J].IEEE J Sel Top Quantum Electron,1999,5(5):1278-1288.

[4] [4] 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[J].IEEE Photon Technol Lett,1999,11(10):1229-1231.

[5] [5] ZHANG Zi-jia,SHI Wen-kang,GAO Kan,et al.Investigation of the Spectral Structures of Long-period Fiber Grating[J].Acta Photonica Sinica,2004,33(11):1308-1312.

[6] [6] CUI Chun-lei,LIU Wei-ping,HUANG Hong-bin,et al.Cladding mode′s characteristic and its affects on transmission spectrum of long period fiber gratings[J].Acta Photonica Sinica,2005,34(10):1569-1572.

[7] [7] LIAW S K,HO K P,CHI S.Dynamic power-equalized EDFA module based on strain tunable fiber Bragg gratings[J].IEEE Photon Technol Lett,1999,11(7):797-799.

[8] [8] WYSOCKI P F,JUDKINS J B,ESPINDOLA R P,et al.Broad-band erbium-deped fiber amplifier flattened beyond 40 nm using Long-Period grating filter[J].IEEE Photonics Technology Letter,1997,9(10):1343-1345.

[9] [9] PANDIT M K,CHIANG K S.Tunable longperiod fiber gratings for EDFA gain and ASE equalization[J].Microwave Opt Technol Lett,1999,25(3):181-184.

[10] [10] ZHU Tao,RAO Yun-jiang,MO Qiu-ju.Ultra-Long period fiber gratings written by High-Frequency laser pulses[J].Acta Photonica Sinica,2005,34(11):1697-1700.

[11] [11] RAO Yun-jiang,WANG Yi-ping,RAN Zeng-ling,et al.Novel fiber-optic sensors based on long-period fiber gratings written by high-frequency laser pulses[J].J Lightwave Technology,2003,21(5):1320-1325.

[12] [12] DESURVIRE E,ZYSKIND J L,GILES C R.Design optimization for efficient erbium-doped fiber amplifiers[J].J Lightwave Technol,1990,8(11):1730-1741.