通过在长周期光纤光栅的某一位置引入一段调制结构形成积累相移,提出了一种新的相移长周期光纤光栅结构的设计方法。基于光纤光栅相位匹配原理,给出了在引入的调制结构为均匀短周期光纤光栅,其折射率调制深度与原光纤光栅一致时,调制结构的参数(光栅周期和长度)与所引起相移大小的关系式,并采用传输矩阵法和CO2激光单面曝光的方法从仿真和实验方面对所提出的结构进行了分析和验证。研究表明:在长周期光纤光栅某点引入一段均匀短周期光栅调制结构能够形成相移长周期光纤光栅,并且当其折射率调制深度与原长周期光纤光栅一致时,形成的相移长周期光纤光栅光谱只与调制结构的长度有关。 A novel phase-shift long-period fiber grating structure design method is proposed by introducing a period of modulation structure to form accumulated phase shift in a certain position of the long-period fiber grating. Based on the principle of fiber grating phase matching, the parameters of the modulation structure (grating period and length) and the induced phase shift size are given when the modulation structure introduced is a uniform short-period fiber grating whose refractive index modulation depth is the same as the original fiber grating The relationship between the proposed method and the transmission matrix method and CO2 laser single exposure method was used to analyze and verify the proposed structure from the simulation and experimental aspects. The research shows that the phase-shift long-period fiber grating can be formed by introducing a uniform short-period grating at a certain point of the long-period fiber grating. When the refractive index modulation depth is the same as the original long-period fiber grating, the phase-shift long- The grating spectrum is only related to the length of the modulation structure.