基于剪切干涉仪和残差网络模型的光学轨道角动量的探测  

Detection of Orbital Angular Momentum of Light Based on Shear Interferometer and Residual Network Model

作　　者：柳冠华 周婧雯 汤继鸿 夏勇[1] Liu Guanhua;Zhou Jingwen;Tang Jihong;Xia Yong(State Key Laboratory of Precision Spectroscopy,Joint Insititute of Advanced Science and Technology,School of Physics and Electronic Science,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学物理与电子科学学院精密光谱科学与技术国家重点实验室,上海200241

出　　处：《激光与光电子学进展》2024年第23期175-182,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(12174115)。

摘　　要：涡旋光束的轨道角动量(OAM)在自由空间光通信中具有重要的应用前景。涡旋光束在传播过程中,大气湍流会影响对OAM模式的探测精度。提出并验证了在大气湍流条件下利用剪切干涉仪和残差网络模型(ResNet-50)来探测OAM模式。推导了经过剪切干涉仪的OAM光束的光场强度分布,给出了适合所提物理模型的大气湍流理论和残差网络模型,研究了训练样本数量对OAM识别准确率的影响和不同湍流强度条件下OAM识别准确率。研究结果表明,OAM光束在传播过程中,当其拓扑荷数l在−4~4范围内,计算机模拟的较弱大气湍流C_(n)^(2)=5×10^(-16)m^(-2/3)时,OAM识别准确率为100%;较强大气湍流C_(n)^(2)=5×10^(-14)m^(-2/3)时,OAM识别准确率为92%。The orbital angular momentum(OAM)of vortex beams has important application prospects in free-space optical communications.During the propagation of vortex beams,atmospheric turbulence can affect the accurate detection of OAM modes.We propose and demonstrate the accurate detection of OAM modes using a shear interferometer and residual network model(ResNet-50)under different atmospheric turbulence conditions.We first derive the optical field intensity distribution of OAM beams after passing them through a shearing interferometer.We then introduce atmospheric turbulence theory and a residual network model suitable for the proposed physical model.Finally,we investigate the effects of training sample size on OAM recognition accuracy and OAM recognition accuracy under different turbulence intensity conditions.Results show that during the propagation of OAM beams,within the range of topological charge l of-4―4 and under weak atmospheric turbulence simulated by computers at C_(n)^(2)=5×10^(-16)m^(-2/3),the OAM recognition accuracy is 100%.Under strong atmospheric turbulence simulated at C_(n)^(2)=5×10^(-14)m^(-2/3),the OAM recognition accuracy is 92%.

关 键 词：涡旋光束 轨道角动量 剪切干涉仪 空间光调制器 机器学习 

分 类 号：O43[机械工程—光学工程]