提出并制作出一种基于锥体光纤-长周期光纤光栅-锥体光纤结构的全光纤Mach-Zehnder(M-Z)干涉仪传感器, 并对其温度传感特性进行了研究.实验结果表明, 固定光纤锥体和长周期光纤光栅的结构, 仅改变两个光纤锥体之间的距离, 对应不同的M-Z干涉谐振峰呈现出不同的温度传感特性: 随着两个光纤锥体之间的距离增加, 位于短波长处的谐振峰, 传感器的温度灵敏度减小, 而位于长波长处的谐振峰, 传感器的温度灵敏度增加.当传感器长度为16.5 cm时, 在1 680 nm附近的温度灵敏度达到0.102 06 nm/℃.实验结果对于锥体光纤-长周期光纤光栅组合型温度传感器的优化设计具有重要参考价值.

An all-fiber Mach-Zehnder interferometer sensor based on Bitaper-LPFG-Bitaper structure is proposed and fabricated, and the temperature sensing characteristic of the sensor is analyzed. The experimental results show that the sensor presents different characteristics at the different resonance wavelengths by changing the distance between the two bitapers, for the fixed structures parameters of the two bitapers and LPFG. The sensitivity of the sensor reduces with the increasing distance between the two bitapers at the shorter resonance wavelength, but increases at the longer resonance wavelength. When the length of the sensor is 16.5 cm, its sensitivity reaches 0.102 06 nm/℃ around 1 680 nm. The research work is important for the optimization design of temperature sensor consisting of bitaper and LPFG.