光子学报, 2010, 39 (2): 238, 网络出版: 2010-05-24
一种通道数可变的光纤光栅梳状滤波器
Hybrid Fiber Grating-based Optical Comb Filters with Changeable Channel Numbers
长周期光纤光栅 梳状滤波器 通道可调滤波器 啁啾光纤光栅 Long-period gratings Comb filters Tunable filters Chirped fiber Bragg gratings
摘要
利用级联长周期光纤光栅与具有宽带反射功能的啁啾光纤光栅,构成了一种反射型的光纤光栅梳状滤波器.由于光在输出前经过两次干涉滤波作用,所以该梳状滤波器的消光比与透射输出型(即反射前)相比,增加了一倍.而且,通过调节啁啾光纤光栅的反射带宽,可以改变滤波器输出信道的数目.实验中利用弹性梁弯曲的方法,获得了两个可调的光纤光栅梳状滤波器,其信道数可分别在1~5和3~9之间的奇数间调谐(如果改变啁啾光纤光栅的初始中心波长,也可以获得偶数信道间的调谐).
Abstract
An in-fiber Mach-Zehnder interferometer filter based on a pair of long-period fiber gratings (LPGs) had been operated in the reflection mode by incorporating a broadband chirped-fiber Bragg grating (CFBG) or an optical fiber mirror reflector.As a result,the extinction ratio has been nearly doubled and,by tuning chirp rate,i.e.reflection bandwidth of the CFBG using a beam-bending method,channel number of the formed optical comb filter can be easily changed.In our experiment,two comb filters with channel numbers being changed among odd ones from 1 to 5 and 3 to 9 have been achieved,respectively.Even channel filtering can also be achieved if the center wavelength of the chirped fiber grating is changable.
董新永, 李岚, 沈平, 陈志超. 一种通道数可变的光纤光栅梳状滤波器[J]. 光子学报, 2010, 39(2): 238. DONG Xin-yong, LI Lan, SHUM Ping, CHAN Chi-chiu. Hybrid Fiber Grating-based Optical Comb Filters with Changeable Channel Numbers[J]. ACTA PHOTONICA SINICA, 2010, 39(2): 238.