基于液晶空间光调制器的激光束散角控制技术  

Laser beam scatter angle control technology based on liquid crystal spatial light modulator

作　　者：王姝懿 刘智[2] 林鹏 刘树通 刘艺 WANG Shu-yi;LIU Zhi;LIN Peng;LIU Shu-tong;LIU Yi(School of Optoelectronic Engineering,Changchun University of Science and Technology,Changchun 130022,China;National and Local Joint Engineering Research Center of Space Optoelectronic Technology,Changchun University of Science and Technology,Changchun 130022,China;School of Electronic and Information Engineering,Changchun University of Science and Technology,Changchun 130022,China)

机构地区：[1]长春理工大学光电工程学院,吉林长春130022 [2]长春理工大学空间光电技术国家地方联合工程研究中心,吉林长春130022 [3]长春理工大学电子信息工程学院,吉林长春130022

出　　处：《液晶与显示》2022年第11期1430-1438,共9页Chinese Journal of Liquid Crystals and Displays

基　　金：国家自然科学基金叶企孙科学基金(No.U2141231);应用光学国家重点实验室开放基金(No.SKLAO2022001A04)。

摘　　要：在远距离激光通信系统中,为抑制复杂大气信道环境的影响,有必要对激光束散角进行实时调控。而传统光学变焦系统对激光束散角的调控精度不高,需要机械移动透镜组间距离,导致其灵活性和实时性差。本文提出了利用液晶空间光调制器(Liquid Crystal Spatial Light Modulator,LC-SLM)控制激光束散角的方法。通过LC-SLM模拟变焦透镜,由计算机生成不同焦距的相位灰度图并导入LC-SLM,利用不同的相位灰度图的灰度信息控制LC-SLM的外加电压以实现变焦透镜的功能;再利用变焦透镜与已知焦距的匹配透镜共同构成束散角控制系统,变焦透镜与匹配透镜距离恒定不变,通过改变变焦透镜的焦距实现束散角控制。研究结果表明,在基于液晶空间光调制器的激光束散角控制方法中,束散角变化值与理论值误差在5%以内,束散角的RMSE为0.017 5。与传统机械移动透镜组间距离控制束散角的方法相比,束散角均方根误差降低了22%,为激光参数动态调整提供了重要技术支撑。In the long distance laser communication system,it is necessary to control the dispersion angle of laser beam in real time in order to suppress the influence of complicated atmospheric channel environment.However,the traditional optical zoom system has low precision in adjusting the laser beam scatter angle,which requires mechanical movement of the distance between the lens groups,resulting in poor flexibility and real-time performance. In this paper,a method of controlling laser beam scatter angle using liquid crystal on spatial light modulator(LC-SLM)is proposed. LC-SLM was used to simulate the zoom lens,and the phase gray images with different focal lengths were generated by computer and imported into LC-SLM.The applied voltage of LC-SLM was controlled by the gray information of different phase gray images to realize the function of the zoom lens. Then,the control system of beam scattering angle was composed of the zoom lens and the matching lens with known focal length. The distance between the zoom lens and the matching lens was constant,and the beam scattering angle was controlled by changing the focal length of the zoom lens. The results show that the error between the variation value and the theoretical value is within5%,and the RMSE of the beam divergence angle is 0. 017 5. The root mean square error of beam divergence angle is reduced by 22% compared with the traditional method of controlling beam divergence angle by mechanically moving the distance between lens groups,which provides an important technical support for dynamic adjustment of laser parameters.

关 键 词：液晶变焦透镜 LC-SLM 束散角 光斑分析 

分 类 号：TN929[电子电信—通信与信息系统]