应用传输矩阵法对相移光纤光栅(FBG)的反射光谱特性作了详细的理论分析, 给出了相应的数学模型, 并进行了验证。结果表明, 相移的引入导致光纤光栅反射谱产生分裂, 分裂点波长与相移大小呈线性正比关系并具有周期性；分裂点反射率与相移位置、光栅中心波长之间具有一定的对称性, 且符合双曲正切关系。

Based on the transfer matrix method,the reflective spectrum characteristics of the phase-shifted fiber grating are analyzed by detailed theoretic. The corresponding mathematical model is established and validated. It is shown that the phase shift leads to the split of the reflective spectrum of the fiber grating. The wavelength of the split point is linearly and periodical to the phase shift. The reflectivity of the split point is symmetrical to the phase-shifted position and the central wavelength of the fiber grating. And the reflectivity of split point is approximately hyperbolically tangential versus the phase-shifted position.