报道了一种基于随机并行梯度下降(SPGD)算法的高消光比非保偏-保偏光自适应偏振转换系统。该系统利用偏振控制器对非保偏光的偏振分量进行直接控制, 通过SPGD算法对输出的偏振消光比进行优化, 最终实现了自适应的非保偏-保偏光的偏振转换。理论上, 结合SPGD算法和偏振控制器的原理, 对系统进行分析, 建立了非保偏-保偏光自适应偏振转换的数学模型。实验上, 利用该系统实现了非保偏到保偏光的转换, 获得了14.1 dB的线偏振光输出；并利用该系统将任意方向(0~360°)偏振态的线偏振光转换为期望偏振态的高消光比线偏光, 其输出线偏光的平均消光比约为12 dB。

The adaptive polarization conversion system which converts the non-polarization maintaining laser to polarization maintaining one based on stochastic parallel gradient descent (SPGD) algorithm is reported in this paper. Using polarization controller to control polarized component in X and Y direction directly, adopting SPGD optimization technology to optimize the output extinction ratio, it finally realizes polarization conversion of non-polarization maintaining laser to polarization maintaining one. In theory, the model of adaptive polarization conversion is built based on the principle of the controller and the SPGD algorithm. In experiment, we first realized adaptive conversion of non-polarization maintaining laser to polarization maintaining one with an extinction ratio of 14.1 dB. Then we used the system to change the polarization direction of the linearly polarized laser from any direction (0-360°) to the expected direction with high extinction ratio, and the average extinction ratio is about 12 dB.