现有保偏光纤侧视成像法多依赖于某特定形貌光强分布, 对成像面位置调整要求高、通用性差。为了提高保偏光纤定轴灵敏度、增加方法的通用性、提高定轴稳定性, 采用双光束光源取代单光束光源对保偏光纤进行侧视成像的方法, 改变了以往通过调整成像面寻找特定形貌光强分布的思路, 并进行了理论分析、仿真模拟和实验验证。结果表明, 采用双光束光源进行侧视成像时, 光强分布成双峰型, 选择双峰光强值之和为特征值, 建立特征值与偏转角度的对应关系, 利用互相关分析可对偏转角进行确定, 该方法不仅保持了透镜效应侧视法适用成像面范围广的优点, 而且定轴灵敏度平均优于单光束光源侧视成像定轴法11.88%。该研究具有良好的实用前景。

The current side-view imaging alignment method for polarization-maintaining fiber depended on the specific light intensity distribution, and had strict requirements on the position adjustment of the imaging plane. In order to improve the sensitivity of the fixed axis, increase the universality of the method and improve the stability of the fixed axis, a double-beam light source was used to replace the single-beam light source for the side-view imaging of the polarization maintaining fiber. The idea of finding the intensity distribution of the specific morphology by adjusting the image plane was changed. After theoretical analysis, simulation and experimental verification, the results show that, when using double-beam light source for side-view imaging, the light intensity distribution has bimodal pattern, and the sum of the bimodal light intensity values is selected as the eigenvalue to establish the corresponding relationship between the eigenvalue and the deflection angle. The deflection angle can be determined by cross-correlation analysis. This method not only maintains the advantages of wide range of imaging planes of polarization observation by the lens effect tracing(POL), but also has an axis sensitivity of 11.88% better than the single-beam side-view imaging alignment method. This method has good application prospects.