中文摘要：

倾斜光纤光栅因其独特的结构在传感和通信领域应用前景广阔。基于模式耦合理论，仿真研究介质折射率对倾斜光纤光栅透射功率谱的影响及其变化规律。研究结果表明，当介质折射率在1．35至1．4之间变化时，本文设计的倾斜光纤光栅透射功率谱包层谐振峰位置随外界介质折射率的增大而逐渐向长波长方向移动，波长偏移量与外界介质折射率之间呈良好的线性关系，利用这个结论可进行介质折射率的测量。

英文摘要：

Tilted fiber bragg grating （TFBG） has a promising application in sensing and communication fields due to their special structure. Based on mode coupling theory, the effect of surrounding refractive index on trans- mission power spectra of TFBG and corresponding changing law were investigated by means of simulation method. The results show that cladding resonance of TFBG shifts to long wavelength with increasing surrounding refractive index with the range of between 1.35 and 1.4, and the shift of wavelength shows a good linear relationship with surrounding refractive index. This conclusion is very useful to measurement for refractive index.