[1] [1] Hill K O,Fujii Y,Johnson D C,et al.Photosensitivity in optical waveguides application to reflection filter fabrection.Appl Phys Lett,1978,32(8):647～649

[2] [2] Vengsarkar A M,Lemaire P J,Judkins J B,et al.Long-period fiber gratings as band-rejection filters.J Lightware Technol,1996,14(1)58～65

[3] [3] Patrick H J,Chang C C,Vohra S T.Long period fibre gratings for structural bend sensing.Electron Lett,1998,34(18):1773～1775

[5] [5] Rao Y J,Zhu T,Ran Z L,et al.Applications of CO2-induced long-period fiber gratings in Er-doped fiber amplifiers.Asia-Pacific Optical Communications Conference and Exhibition 2001,Proceedings of SPIE,4581:319～326

[6] [6] Rao Y J,Wang Y P,Ran Z L,et al.Characteristics of novel long-period fiber gratings written by focused high-frequency CO2 laser pulses.Asia-Pacific Optical and Wireless Communications 2001,Proceedings of SPIE,4581:327～333

[7] [7] Erdongan T.Fiber Grating Spectra.J Lightwave Technol,1997,15(8):1277～1294

[8] [8] MacDougall T W,Pilevar S,Haggans C W,et al.Generalized expression for the growth of long period gratings.IEEE Photonics Technology Letters,1998,10(10):1449～1451

[9] [9] Kumar A,Gallawa R L,Goyal I G.Modal characteristics of bent dual mode planar optical waveguides.J Lightwave Technol,1994,12(4):621～624