采用耦合模分析法研究了旋转磁光光纤中线双折射、光纤旋转以及磁光效应等因素对导波光传播特性的影响.结果表明：1）旋转磁光光纤中本征光波的特征是椭圆率始终保持不变；2）就输入/输出特性而言，旋转磁光光纤可等效为一个等长度的线双折射磁光光纤后跟一个旋转器，该线双折射磁光光纤的磁光耦合系数取决于光纤旋转和磁场加载方式.在此基础上分析了旋转磁光光纤的磁控偏振特性，对于适当的线偏振光入射情形，通过改变磁光耦合系数可实现输出偏振光椭圆率从－1到+1的线性连续可调，同时也伴随着方位角的线性改变，据此可进一步设计出具有磁可调功能的新型偏振控制器.

According to the coupledmode method, the propagation of guided optical waves in spun magnetooptic fibers (SMOFs) was investigated by considering the coupling of linear birefringence, fiber spun and the magnetooptic (MO) effect. The results show that, 1) the SMOF′s eigen optical waves are of constant ellipticity along the SMOF; 2) from the viewpoint of input/output properties, the SMOF may be regarded as a linearly birefringent MO fiber (LBMOF) followed by a polarization rotator, in which the LBMOF has the same length as the SMOF and its MO coupling coefficient is equal to that of the SMOF minus fiber rotation ratio. The polarization characteristics of the SMOF under magnetic control were analyzed as well. For the case of incident linear polarization, the ellipticity and azimuth of light output from the SMOF can be linearly adjusted by changing the MO coupling coefficient or magnetic field, which is helpful for the design of magnetically tunable polarization controllers.