将长周期光纤光栅(LPG)和光纤Sagnac环相结合,实现了折射率和温度的同时测量.首先利用二氧化碳激光器在保偏光纤上制作了长周期光纤光栅(PM-LPG),然后把该PM-LPG和普通单模光纤耦合器组成Sagnac环,作为传感单元.实验选择其某一透射峰作为测试对象,其波长随温度变化,强度随折射率变化,因此可实现两个参量的同时测量.实验获得的温度灵敏度为-0.654 nm·℃-1,折射率灵敏度为49.9dB·RIU-1.整个实验系统成本低、简单实用,具有较好的应用前景.%By inscribing a long-period fiber grating (LPG) on a polarization-maintaining fiber (PMF), a fiber Sagnac loop sensor for simultaneous measurement of refractive index and temperature has been proposed and demonstrated. The LPG was fabricated on the PMF by using a CO2 laser, and then inserted into a fiber loop formed by using a normal single-mode fiber coupler. One of the transmission minimum of the Sagnac loop sensor was measured, whose wavelength varied with temperature and the intensity changed with refractive index. Temperature sensitivity of -0. 654 nm · ℃ -1 and refractive sensitivity of 49. 9 dB · RIU-1 havebeen achieved. The sensor system shows advantages of small size and low cost, and owns a good application prospect.
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