Xie Guodong, Ren Yongxiong, Huang Hao, Lavery Martin P J, Ahmed Nisar, Yan Yan, Bao Changjing, Li Long, Zhao Zhe, Cao Yinwen, Willner Moshe, Tur Moshe, Dolinar Samuel J, Boyd Robert W, Shapiro Jeffrey H, Willner Alan E
Opt Lett. 2015 Apr 1;40(7):1197-200. doi: 10.1364/OL.40.001197.
A stochastic-parallel-gradient-descent algorithm (SPGD) based on Zernike polynomials is proposed to generate the phase correction pattern for a distorted orbital angular momentum (OAM) beam. The Zernike-polynomial coefficients for the correction pattern are obtained by monitoring the intensity profile of the distorted OAM beam through an iteration-based feedback loop. We implement this scheme and experimentally show that the proposed approach improves the quality of the turbulence-distorted OAM beam. Moreover, we apply phase correction patterns derived from a probe OAM beam through emulated turbulence to correct other OAM beams transmitted through the same turbulence. Our experimental results show that the patterns derived this way simultaneously correct multiple OAM beams propagating through the same turbulence, and the crosstalk among these modes is reduced by more than 5 dB.
提出了一种基于泽尼克多项式的随机并行梯度下降算法（SPGD），用于生成扭曲轨道角动量（OAM）光束的相位校正图案。通过基于迭代的反馈回路监测扭曲OAM光束的强度分布，获得校正图案的泽尼克多项式系数。我们实施了该方案，并通过实验表明，所提出的方法提高了湍流扭曲OAM光束的质量。此外，我们应用通过模拟湍流从探测OAM光束导出的相位校正图案来校正通过相同湍流传输的其他OAM光束。我们的实验结果表明，以这种方式导出的图案同时校正了通过相同湍流传播的多个OAM光束，并且这些模式之间的串扰降低了超过5 dB。
