对匹配型保偏光纤自动对轴技术进行了研究.介绍了透镜效应法(POL)对轴原理,由此设计了一套自动对轴系统并进行了性能测试.利用所设计的对轴平台进行了一系列实验,发现不同观测物平面光纤成像存在不同的光强分布特征,其中五点特征的光强分布对应的物平面范围最宽,对轴时不需要费时调焦.对五点随光纤方位角的变化规律曲线进行了分析,提出了五点特征值法.与原来的透镜效应法相比,此法对轴更简单,而且具有更高的测量精度,更适合于自动对轴系统.

The auto-alignment technique is studied for the PM fiber (PMF) of matching refractive-index(MRI). The polarization observation by lens-effect-tracing technique(POL) is introduced. Based on the POL,an auto-alignment system is designed and its performance is then tested. Different light-intensity distribution characteristic is found on the different observation surfaces in a series of experients. The widest range of adjustment is achieved when the observation surface corresponds to a light-intensity distribution with five characteristic points. This means it is easier to focus.The five-point method is presented after analysis of the curves of the five characteristic points with respect to the azimuth angle of the optical fiber.By comparison with the POL,this method is easier to be realized and has higher measurement accuracy,so it is suitable for auto-alignment system.