双光栅耦合器型上下话路滤波器的设计和实验  

Design and Experiment of Add/Drop Filter Based on Double-Fiber-Bragg-Gratings Coupler

作　　者：董小伟[1] 许鸥[1] 鲁韶华[1] 冯素春[1] 裴丽[1] 简水生[1] 

机构地区：[1]全光网与现代通信网教育部重点实验室北京交通大学光波技术研究所,北京100044

出　　处：《中国激光》2007年第8期1106-1109,共4页Chinese Journal of Lasers

基　　金：国家自然科学基金(60477017);北京市自然科学基金(4052023);北京交通大学人才基金(2007RC015)资助项目

摘　　要：利用两布拉格光栅反射作用的联合效应形成的双光栅耦合器,具有结构紧凑、滤波效率显著加强的优点.通过详细分析光栅写入特性对器件性能的影响,指出优化光栅在耦合区中的位置,不仅可以使得满足布拉格匹配条件的信号最大效率地下话路输出,还能有效消除背向回波干扰.在此基础上,调节光栅写入长度和紫外折射率调制强度,设计制作出一种结构平衡、上下话路滤波响应同时改善的新型双光栅耦合器.并且在实验中发现,耦合区的非均匀是造成下话路响应平坦性恶化的主要因素,为改进熔融拉锥工艺、进一步提高双光栅耦合器的滤波性能提供了依据.　Double-grating coupler based on two fiber-Bragg-gratings（FBGs） has the advantages of compact structure and enhanced filtering efficiency.The influences of gratings′ characteristics were investigated thoroughly,and the result showed that maximum drop efficiency and minimum backreflected return wave could be achieved by choosing proper gratings′ position in the coupler region.Furthermore,by adjusting the gratings′ length and ultraviolet（UV） refractive modulation depth,a novel balanced configuration with the two Bragg gratings inscribed into the coupler waist′s center was designed and fabricated,which showed simultaneously optimized add and drop filtering responses.The experimental measurement demonstrated that the uniformity of coupler waist should be responsible for the inequality in drop bandpass,and the filtering performance of double-gratings coupler can be enhanced by improving fused taper technique.

关 键 词：光通信 上下话路滤波器 光纤耦合器 光纤布拉格光栅 熔融拉锥 

分 类 号：TN253[电子电信—物理电子学] TN929.11