在失配光纤耦合器的一个光纤上写入布拉格光栅构成的光栅辅助耦合器，对光栅处于耦合区中的位置不敏感，性能稳定，具有非干涉型器件的优点。通过改进的熔融拉锥工艺，利用康宁SMF-28和光敏光纤制作了具有均匀耦合区的耦合器，使用波长为248 nm的紫外激光在均匀耦合区的光敏光纤上写入布拉格光栅，实验获得了最大反射率为15 dB,透射深度4 dB,带宽为0.1 nm的窄带光栅辅助耦合器，能够满足密集波分复用(DWDM)系统的需求；并详细地分析了耦合区非均匀性对下话路特性的影响；将制成的器件在10 Gb/s的光纤传输系统中进行下话路测试，比较背靠背眼图与使用光栅辅助耦合器下话路后的眼图，结果表明其具有很好的滤波性能。

Grating assisted coupler which consists of a mismatched coupler with a Bragg grating written in only one core over the coupling region is a kind of non-interference device, so it is stable in performance and doesn’t depend on the position of the grating in the coupler region.A coupler with uniform coupling region making of SMF-28 and photoconductive fiber is fabricated by improved fused taper technology,then a Bragg grating is written in the coupling region with 248 nm ultraviolet laser,and a narrow bandwidth grating assisted coupler with maximum about reflectivity 15 dB, transmission 4 dB and bandwidth 0.1 nm is achieved to satisfy the dense wavelength division multiplexing (DWDM) system; The effect of the uniformity of coupler on the response is studyed; Its filter performance is tested in the 10 Gb/s fiber optic transmission system, and the results show that the device has good performance.