基于图像的保偏光子晶体光纤定轴技术研究

Research on image-based polarization-maintaining photonic crystal fiber alignment technology

分析保偏光子晶体光纤定轴的精度并进行实验验证。误差计算表明,空气孔中心提取算法精度越高、定轴空气孔中心距越大,定轴误差越小。算法精度分析表明,空气孔中心提取算法精度达到亚像素,圆心横坐标误差小于0. 2个像素,采用快轴轴线上中心距最大的两个小空气孔定轴,定轴误差小于0. 15°。相机实时采集端面图像,定位空气孔中心后求出旋转角,利用电机细分驱动转动保偏光子晶体光纤。准确度实验说明定轴算法可靠,精密度实验说明定轴算法稳定,最后的定轴实验证明,定轴技术可行,且能达到±0. 2°的定轴精度,易于推广到其他光子晶体光纤定轴。

The accuracy of the fixed axis of polarization-maintaining photonic crystal fiber is discussed and verified by experiments. The error analysis shows that the higher the accuracy of the air hole center extraction algorithm,the larger the center distance of the fixed air hole,and the smaller the fixed axis error. The accuracy calculation of the algorithm shows that air hole center extraction algorithm achieves sub-pixel accuracy,and the center of the circle has an error of less than 0. 2 pixels. The fixed axis error is minimized by using two small air holes with the largest center distance on the fast axis,fixed axis error is less than 0. 15°. The camera collects the end image in real time,and locates the center of the air hole to find the rotation angle,and uses the motor subdivision to drive the rotation preserving photonic crystal fiber. Accuracy experiments show that the fixed axis algorithm is reliable,the precision experiment shows that the fixed axis algorithm is stable,and the final fixed axis experiment proves that the fixed axis technology is feasible,and can achieve the fixed axis accuracy of ±0. 2°,which is easy to be applied to other photonic crystal fiber.