利用传输矩阵法分析了磁光效应和光栅折射率初始相位对磁光光纤布拉格光栅(MFBG)-法布里-珀罗(FP)光谱特性的影响。通过调节外加磁场的大小及方向,能实现MFBG-FP的可调滤波特性,并能控制甚至抵消光栅折射率初始相位差引起的透射峰平移。对于高光栅反射率的MFBG-FP,透射峰位置和波长间隔可由其有效腔长以及等效磁光耦合系数来解析表达。MFBG-FP的磁可调能力会随着FP腔与MFBG的磁光耦合系数比的增加而增强,磁光耦合系数比大于1的MFBG-FP结构的磁可调特性优于相应的MFBG结构。 The influence of magneto-optic effect and the initial phase of grating refractive index on the spectral properties of magneto-optic fiber Bragg grating (MFBG) -Fabry-Perot (FP) was analyzed by transmission matrix method. By adjusting the size and direction of the applied magnetic field, the MFBG-FP tunable filter characteristics can be achieved, and the transmission peak shift caused by the initial retardation of the grating refractive index can be controlled or even canceled. For MFBG-FP with high grating reflectance, the transmission peak position and wavelength separation can be analytically expressed by their effective cavity length and the equivalent magneto-optical coupling coefficient. The MFR of MFBG-FP is enhanced with the increase of the ratio of the magneto-optic coupling between the FP cavity and the MFBG. The MFBG-FP structure is better than the corresponding MFBG structure in the magnetically tunable MFBG-FP structure.