基于机器学习检测相位畸变后的涡旋光束轨道角动量  

Detect the Orbital Angular Momentum of Vortex Beams after Phase Distortion Based on Machine Learning

作　　者：史晨寅 韦宏艳 贾鹏 岳新宇 SHI Chenyin;WEI Hongyan;JIA Peng;YUE Xinyu(College of Physics and Optoelectronics,Taiyuan University of Technology,Taiyuan 030006,China)

机构地区：[1]太原理工大学物理与光电工程学院,太原030006

出　　处：《光子学报》2022年第1期319-326,共8页Acta Photonica Sinica

基　　金：国家自然科学基金(No.61805173);陕西省自然科学基金(No.2019JQ-901)。

摘　　要：针对涡旋光受大气湍流而产生的相位畸变问题,设计了卷积神经网络检测涡旋光束轨道角动量态。将相位畸变的拉盖尔高斯涡旋光光强图像作为样本数据输入,网络利用输入的数据集进行自主学习,经过多次迭代能够精确检测出光束高阶轨道角动量信息。仿真结果表明:在大气湍流强度不确定的情况下,模型对轨道角动量态范围为1~40、1~100、1~160的涡旋光束检测准确率分别为94%、90%、86%;在不同传输距离、不同径向指数、不同基模束腰半径以及不同波长下轨道角动量态范围为1~100的涡旋光束的检测准确率均达到78%以上,且具有很好的鲁棒性。该方法检测精度高、范围广、移植性强,可为涡旋光束轨道角动量态的检测与识别提供一种新思路。Vortex beams carrying orbital angular momentum can be used in free space optical communication and have greater data coding freedom. However,the atmospheric turbulence channel is the key factor that limits the performance of vortex free space optical communication. It carries different random disturbances of the Laguerre Gaussian beam wavefront phase with orbital angular momentum modes,so it cannot keep its original orthogonality;it may cause serious signal crosstalk and receive light signal phases and intensities of ups and downs. When the vortex beams carrying information are transmitted in the atmospheric channel,it will be disturbed by turbulence and cause phase distortion. Vortex beam orbital angular momentum detection methods mainly include optical methods and machine learning methods. However,the optical method needs to use more communication system elements,the operation is complicated and the detection of vortex beams with phase disturbance is not involved. At the same time,the current machine learning methods have not involved the detection of high range orbital angular momentum modes so far,and need to know the prior knowledge of atmospheric turbulence. Aiming at the problem of measuring the orbital angular momentum mode information of vortex beams after phase distortion,this paper proposes a method to detect the orbital angular momentum mode information of vortex beams disturbed by atmospheric turbulence by using the designed convolutional neural network. A turbulence model of anisotropic atmospheric turbulence is established based on the multiphase screening method. Laguerre Gaussian beams with different beam parameters are transmitted in the simulated turbulence channel,and the intensity image of the Laguerre Gaussian vortex beam with phase distortion is obtained at the receiver end. In addition,the size of the receiver plate is fixed,and different sizes of the receiver plate are used to receive vortex beams with different ranges of orbital angular momentum. Due to the randomness of atmospheric turb

关 键 词：涡旋光束 湍流扰动 卷积神经网络 高轨道角动量态检测 相位畸变 

分 类 号：TN929.12[电子电信—通信与信息系统]