光纤布拉格光栅温度和应变交叉灵敏度的实验研究

Experimental Study on Cross-sensitivity of Temperature and Strain of Fiber Optic Bragg Gratings

测量了光纤布拉格光栅(FBG)在-150～550 ℃范围内中心反射波长对应变的依赖关系,得到了光栅的温度和应变交叉灵敏度系数.结果表明,不论是在低温环境还是高温环境,当光纤所受张力小于6 000 με时,波长变化与应变大小呈线性关系;光栅的应变灵敏度系数和交叉灵敏度系数是温度的函数,温度越低,应变灵敏度系数越大,交叉影响越显著.

The strain response of fiber Bragg grating sensors was measured at a constant temperature. Strain sensitivity coefficient and cross-sensitivity coefficient were obtained at temperatures from -150°C to 550°C. It is found that the two kinds of strains are the functions of temperature. The strain coefficient will slowly decrease with temperature increasing at higher temperature, and the cross coupling effect is not obvious; the strain coefficient will increase with temperature decreasing at lower temperature, and the cross coupling effect becomes obvious. In addition, the wavelength shift of fiber Bragg gratings changes linearly with applied tensile strain within 6000 μΕ at a constant temperature.