光纤端面进行斜面抛光一直是高功率光纤放大器中抑制ASE和自激振荡的关键技术。根据放大器结构建立了光纤端面信号光注入、信号激光输出以及泵浦光耦合的物理模型，数值模拟了不同光纤斜端面角度下信号光、泵浦光的耦合效率，纤芯端面的回波损耗。结果表明信号光注入端面斜面处理会导致耦合效率降低，输出端面斜角处理可有效减小端面反射率，而微小斜角对泵浦激光进入光纤内包层的耦合效率影响不大；根据不同的光纤参数选择合理的斜角处理可以有效提高放大器性能。

The fiber end with polished inclined-surface is important to reduce the ASE and restrain the selfoscillations for the high power fiber amplifier. Physical models of fiber end with different signal input,output and coupling of pump light are set up. Theoretical analysis,numerical simulation of coupling efficiency and return loss of the fiber end with variable angles of the inclined surface are performed. The results show that the coupling efficiency and return loss of the signal light are affected obviously by the fiber inclined angle,which can improve the performance of the fiber amplifier if the angle is choosen properly.