为解决长周期光纤光栅 (LPG)折射率测量时的温度交叉敏感问题, 利用布喇格光纤光栅 (FBG)对环境折射率不敏感的特点, 将其与长周期光纤光栅 (LPG)级联, 构成具有温度补偿的折射率传感方案。实验结果表明: 随着温度的变化级联光栅的两个透射谐振波长都有线性变化, 而改变溶液折射率时只有一个透射谐振波长改变。因此, 可以利用级联光栅对折射率和温度双参量进行同时测量, 补偿因温度变化产生的测量误差。

In order to solve the sensitivity problem of the temperature in the solution refractive index measurement, a new scheme for refractive index sensing with cascaded Long-period Grating(LPG) and Fiber Bragg Grating(FBG) was presented by using insensitive to refractive index of fiber Bragg grating.The results show that the two resonance wavelength of cascaded fiber grating possesses linearity with the change of temperature, however, only one resonance wavelength shift with the change of the solution refractive index.Thus by using the cascaded fiber grating, we can simultaneously measure the refractive index and temperature, to compensate measuring error by temperature variations.