基于490 nm垂直外腔面发射激光器的长距离水下激光通信系统  

Long-range underwater wireless optical communication system based on 490 nm vertical-external-cavity surface-emitting laser

作　　者：王涛 王章行 沈小雨 朱仁江[1] 蒋丽丹[1] 陆寰宇 路永乐[3] 宋晏蓉[4] 张鹏[5] Wang Tao;Wang Zhang-Xing;Shen Xiao-Yu;Zhu Ren-Jiang;Jiang Li-Dan;Lu Huan-Yu;Lu Yong-Le;Song Yan-Rong;Zhang Peng(College of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;Chongqing University of Posts and Telecommunications,Chongqing 400065,China;School of Physics and Optoelectronic Engineering,Beijing University of Technology,Beijing 100124,China;National Center for Applied Mathematics in Chongqing,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]重庆师范大学物理与电子工程学院,重庆401331 [2]中国科学院长春光学精密机械与物理研究所,长春130033 [3]重庆邮电大学,重庆400065 [4]北京工业大学物理与光电工程学院,北京100124 [5]重庆师范大学,重庆国家应用数学中心,重庆401331

出　　处：《物理学报》2024年第17期169-177,共9页Acta Physica Sinica

基　　金：重庆市自然科学基金(批准号:CSTB2024NSCQ-MSX0833);国家自然科学基金(批准号:61975003,61790584,62025506);重庆市教委科技研究计划(批准号:KJQN202200557,KJQN202300525);在渝本科高校与中国科学院所属院所合作项目(批准号:HZ2021007);重庆师范大学(人才引进/博士点)基金(批准号:23XLB003)资助的课题.

摘　　要：水下无线光通信技术为深海勘探和海洋资源开发利用带来了一种效率高且可靠性强的通信新方案.本文采用490 nm垂直外腔面发射激光器作为光源,基于声光外调制技术,采用脉冲位置调制方式(pulseposition modulation,PPM)搭建了长距离水下无线光通信系统.结合光源的优势并经过软判决算法优化PPM解调来提升水下通信性能,采用64 PPM调制,成功实现了96 m的水下传输距离,在50 MHz时隙频率下得到传输的误码率为1.9×10^(-5).同时测量到采用软判决解调相较于硬判决解调在性能增益上有着大约2 dB的提升,验证了软判决算法在提升水下通信性能方面相比硬判决算法的显著优势.The exploration and utilization of marine resources has promoted the rapid development of marine science and technology,and has put forward higher requirements for underwater communication technology.Long distance underwater wireless optical communication(UWOC)requires the selection of light source on the transmitter side.Laser diodes(LDs)have excellent portability and maneuverability,and have been widely used in the UWOC systems.However,their beam quality is not so good and it is difficult to modulate under high power.In recent years,vertical-external-cavity surface-emitting laser(VECSEL)has received much attention due to its high output power and good beam quality.This work is to explore the advantages of using a 490-nm blue VECSEL as a light source in UWOC,and to improve the performance of the UWOC system by the softdecision pulse-position modulation(PPM).First,the optical power attenuation coefficient of the channel is obtained,and the measured c is about 0.0591 m^(-1) in a 96-m-long tap channel.Subsequently,soft-decision and hard-decision are simulated and experimentally verified.Both simulations and measurements show that the bit error rate(BER)can be significantly reduced with soft-decision.Afterwards,we improve the system by using the soft-decision algorithm and investigate the communication performance of 64 PPMs at different bandwidths by adjusting the PPM signal rate.Finally,50 MHz is chosen as a signal rate in the experiment.Then a UWOC system is demonstrated in this work.The transmitter side consists of a 490-nm VECSEL light source with an acousto-optic modulator(AOM).The pseudo-random binary sequence(PRBS)is loaded into the arbitrary waveform generator(AWG)for digital-to-analog conversion after PPM modulation,and the analog signal is sent to the driver of the AOM for acousto-optic modulation of the incident beam.The laser is focused before entering the AOM and then collimated after having exited to reduce its divergence.The modulated laser beam passes through a distance of 96 m in the tank by using

关 键 词：垂直外腔面发射激光器 脉冲位置调制 软判决算法 水下无线光通信 

分 类 号：TN248[电子电信—物理电子学] TN929.1