镀膜相移长周期光纤光栅滤波特性  

Filter Characteristics of Phase-Shifted Long Period Fiber Grating with Film Coating

作　　者：顾铮■ 蒋秀丽[1,2] 赵晓云[1] 

机构地区：[1]上海理工大学理学院,上海200093 [2]上海电力学院数理系,上海200090

出　　处：《光学学报》2010年第3期633-637,共5页Acta Optica Sinica

基　　金：国家自然科学基金(60777035);教育部重点科研项目(208040);上海市教育委员会科研项目(07ZZ87);上海市重点学科建设(T0501)资助课题

摘　　要：镀膜相移长周期光纤光栅(PS-LPFG)由于其结构及设计的灵活性可以改善光纤光栅的滤波特性。运用传输矩阵法,讨论了在镀膜PS-LPFG中不同位置引入单个相移、多个π相移时传输谱的滤波特性。研究发现,引入单个π相移时,会在谐振波长两侧出现两个新的阻带;引入多个π相移时,两个主阻带峰间隔随相移个数的增多而增大。进一步研究表明,薄膜厚度可以更灵活地调节镀膜PS-LPFG传输谱损耗峰的位置及损耗峰大小。随着薄膜厚度的增加,两损耗峰的位置向短波长方向移动,当薄膜厚度增大到一定值后,损耗峰位置向长波方向发生较大突变,同时损耗峰峰值急剧减小,随后损耗峰又将向短波方向移动且峰值逐渐增大。波长较大的损耗峰变化滞后于波长较小的损耗峰。Phase-shifted long-period fiber grating（PS-LPFG） with film coating can improve the filtering characteristics of fiber grating due to its flexible structure and design.Based on transfer matrix method,the filter characteristics of PS-LPFG with film coating inserted by one phase-shift at different position or manyπphase-shifts are analyzed.The results show that two new stop-bands appear at both sides of the resonant wavelength when a singleπphase shift is inserted,and the interval of the two stop-bands increase with the number of phase-shifts inserted.Further studies indicate that the film thickness can adjust flexibly the location and amplitude of the loss peak.As the film thickness increases,the two loss peaks shift toward the shorter wavelength.When the film thickness increases to a certain value,the loss peaks jump to the longer wavelength,and meanwhile,the amplitudes of the loss peaks decrease rapidly.Subsequently,the loss peaks shift toward the short-wave direction again and the amplitudes increase with the film thickness.In addition,the changes of longer wavelength peaks lag behind the shorter wavelength peaks.

关 键 词：导波与光纤光学 镀膜相移长周期光纤光栅 传输矩阵 薄膜厚度 损耗峰 

分 类 号：TN253[电子电信—物理电子学]