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). Using a cascaded long-period fiber grating and a chirped fiber grating with broadband reflection, a reflective fiber grating comb filter is constructed. Since the light passes through two interference filters before being output, the comb filter The extinction ratio is doubled compared with that of the transmissive output type (ie, before reflection), and the number of filter output channels can be changed by adjusting the reflection bandwidth of the chirped fiber grating.In the experiment, by using the method of bending the elastic beam, Two tunable fiber grating comb filters are obtained, whose number of channels can be tuned oddly between 1 ~ 5 and 3 ~ 9, respectively (even channels can be obtained if the initial central wavelength of the chirped fiber grating is changed) Between the tuning).