自由空间光通信中被动调制研究进展

Research Progress of Passive Modulation in Free Space Optical Communication

【目的】传统的自由空间光(FSO)通信需要参与通信的两端同时安装激光发射系统、激光接收系统和捕获、追踪和瞄准系统,使得系统的重量、体积、功耗、设备复杂程度和技术难度被迫提升,限制了FSO通信的发展。而利用非对称空间激光通信链路构建的被动调制技术,能够实现通信端体积小、重量轻和功耗低的设计,为自由空间激光通信技术在中小型场景中的应用提供了便利。【方法】文章对被动调制的原理及其调制形式进行了阐述,介绍了逆向调制系统的组成和逆向调制器(MRR)的工作原理,对常见MRR如角反射器MRR和“猫眼”MRR进行了分析,并对波长的选择以及光学接收器口径的大小进行了探讨。【结果】总结了被动调制的不同实现类型和特点,概括了其在FSO通信中的应用,展望了该技术未来的发展方向和前景。【结论】被动调制在未来可沿着高速率、焦平面像素化、双向通信和相干检测等方向发展并且有较大的发展空间。

【Objective】Traditional Free Space Optical(FSO)communication requires both ends of the communication to be in stalled at the same time,including the laser transmitting system,laser receiving system and acquisition,tracking and aiming sys tem.It results in the problems of weight,volume,power consumption,and equipment complexity,thus limiting the development of FSO communication.Using the passive modulation technology constructed by asymmetric space laser communication link,the design of small volume,light weight and low power consumption of the communication terminal is successfully realized,which provides convenience for the application of small and medium⁃sized space laser communication technology.【Methods】In this pa per,the research status of passive modulation at home and abroad is reviewed,which is mainly summarized abroad.In addition,the composition of the reverse modulation system and the working principle of the reverse modulator are described.Common Modulated Retro⁃Reflector(MRR)such as angle reflector reverse modulator and cat’s eye reverse modulator are analyzed.The selection of wavelength and the size of optical receiver aperture are discussed.【Results】This paper summarizes the different imple mentation types and characteristics of passive modulation,summarizes the application of passive modulation in FSO communica tion,and looks forward to the future development direction and prospect of this technology.【Conclusion】In the future,passive modulation can be developed along the direction of high speed,focal plane pixelation,two⁃way communication,coherent detec tion,and there is a lot of room for development.This paper can provide a reference direction for the research of passive modula tion and a new idea for the research of FSO communication.