中文摘要：

利用光栅效应和保偏光纤的双折射效应相消原理，设计并制备了一种折射率不敏感温度传感器。传感器由写在熊猫保偏光纤（PMF）上的倾角为45。的长周期光纤光栅（LPFG）对构成。实验结果表明，当满足特定条件时随着环境折射率的变化，谐振波长零漂移；随着环境温度的升高，谐振波长向长波方向漂移，温度灵敏度高达37pm／℃，高于报道的螺旋型折射率调制级联光栅对（温度灵敏度为30pm／℃），三倍于Bragg光栅的温度灵敏度（10pm／℃）。这种结构具有的折射率不敏感性，特别适用于生产过程中液体的温度测量，而不必考虑折射率和温度的交叉敏感性。

英文摘要：

A novel and simple refractive index insensitive temperature sensor, which consists of 45°-tilted long period fiber grating （LPFG） pair inscribed in PANDA polarization-maintaining fiber （PMF） by u- sing focused high-frequency CO2 laser,is proposed in this paper. The mechanism of refractive index insensitivity originates from the destructive theory of grating effect and birefringence effect of polarization maintaining. Experimental results indicate that the peaks with different temperature sensitivities linearly shift towards longer wavelength with temperature. The maximum temperature sensitivity reaches up to 37 pm/°C ,which is larger than that acquired by cascading two special long-period fiber gratings with rotary refractive index modulation （30 pm/°C）, and is 3 times larger than that acquired by using un-tilted Bragg fiber gratings （about 10 pin/°C）. What＇s more, the proposed sensor is insensitive to ambient refractive index when specific conditions are matched. Such a sensor is more suitable for liquid temperature measurement without considering cross sensitivity in actual industrial production.