熊猫型保偏光纤模间干涉的传感特性研究

Research on the sensing characteristics of modular interference in panda-fiber

分析了熊猫型保偏光纤模间干涉输出光强分布同模间干涉相位差之间的关系,并给出了其分布图;采用有限元法对熊猫型保偏光纤的模传输特性进行了计算,得到了几个低阶模式的传输特性曲线;理论计算了LP01模和LP11模间的干涉拍长。通过实验,验证了熊猫光纤模间干涉输出两个干涉边瓣光强随光纤应力变化呈交替分布的特点以及模间干涉拍长的计算结果。本文的研究为将熊猫型保偏光纤应用到光纤传感器的设计中提供了理论和实验参考。

In this paper, the relationship between the output interference light intensity and the modular phase difference in panda fiber is investigated, and the modular interference patters are given. The propagation characteristics of several lower order modes in panda fiber are calculated with finite element analysis method. And the modular interference beat length of LP01 and LP11 is presented theoretically. An experiment is conducted to demonstrate that two-lobe interference output patterns oscillate with each other when the strain is applied on the fiber. And the simulation result of the modular interference beat length is validated also. The results in this paper provide theory foundation and experimental verification for building novel fiber-optic sensors based on the modular interference technology with panda fiber.