基于光波导理论和传输矩阵法,研究了光纤Bragg光栅(FBG)折射率传感器在非均匀液相介质下的响应特性。在数值计算中,分别考虑高折射率区(1.42～包层折射率)和低折射率区(1.33～1.36)两种情况,并假设非均匀液相介质的折射率分布为线性函数,仿真结果表明,FBG的反射谱特性强烈依赖于介质折射率分布函数的某些特征参数,比如折射率沿FBG轴向的分布梯度、折射率在FBG两端的差值。研究结果对FBG折射率传感器在生化传感中的应用具有一定意义。 Based on the optical waveguide theory and the transfer matrix method, the response characteristics of fiber Bragg grating (FBG) refractive index sensors under non-uniform liquid medium are studied. In numerical calculation, two cases of high refractive index region (1.42 ~ cladding index) and low refractive index region (1.33 ~ 1.36) are respectively considered, and the refractive index distribution of the inhomogeneous liquid medium is assumed to be a linear function. The simulation results It is shown that the reflection spectrum of FBG strongly depends on some characteristic parameters of the refractive index distribution function of the medium, such as the distribution gradient of the refractive index along the FBG axis and the difference of the refractive index at both ends of the FBG. The research results have certain significance for the application of FBG refractive index sensor in biochemical sensing.