利用复模式耦合模理论分析了基于闪耀光纤布拉格(Bragg)光栅功率检测的折射计中不同设计参数对折射计性能的影响。利用完全匹配层(PML)技术简化了辐射模分析模型。分析结果表明,随着光栅倾斜角度的增大,折射计的感应范围向折射率较小的方向移动。随着光栅长度以及折射率调制强度的增大,折射计的灵敏度增大,但折射率感应范围不变。同时这种折射计具有偏振依赖性,随着光栅倾斜角的增大偏振依赖性提高。因此在这种传感系统中需要引入精确且稳定的偏振控制。 The effects of different design parameters on the performance of refractometer based on the complex mode coupling theory are analyzed based on the Bragg grating power detection of the blazed fiber. The radiation pattern analysis model is simplified using perfect matching layer (PML) techniques. The analysis results show that with the increase of grating tilt angle, the sensing range of refractometer moves to the direction of smaller refractive index. As the length of the grating and the intensity of the refractive index modulation increase, the sensitivity of the refractometer increases, but the refractive index sensing range does not change. At the same time, this refractometer has a polarization dependence, and the polarization dependency increases as the tilt angle of the grating increases. Therefore, it is necessary to introduce accurate and stable polarization control in this sensing system.