非对称熔锥法制作光纤光栅辅助耦合器型上下话路滤波器

通过在失配光纤消逝场间的耦合作用中引入光栅调制扰动效应，推导出用于解释光栅辅助耦合器响应特征的耦合模方程，在此基础上全面分析了两光纤间的失配度对上下话路滤波性能的影响.采用非对称熔融预拉锥工艺，调整光纤的结构参数，制成了性能良好的光栅辅助耦合器，实验测试结果与理论计算符合得很好. 关键词： 光纤光栅 光纤耦合器 上下话路滤波器 熔融预拉锥

Add/drop channel filter based on fiber-Bragg-grating-assisted coupler fabricated by asymmetric fused taper technology

All-fiber add/drop filter based on fiber-Bragg-grating (FBG) assisted coupler is compact and non-interferometric, which reduces the device's sensitivity to the grating position. By introducing the grating refractive modulation into the evanescent field coupling, the coupled-mode equation of FBG-assisted coupler is obtained and the influences of fiber mismatch on the filter spectra is investigated thoroughly. And a high-quality FBG-assisted filter is achieved by adjusting fiber structure parameters using asymmetric fused taper technology. The experimentally measured results are in good agreement with the numerical calculations.