基于光纤激光相控阵的空间激光通信研究

发布时间：2018-04-04 16:38

本文选题：空间激光通信　切入点：光学相控阵　出处：《长春理工大学》2017年硕士论文

【摘要】：目前自由空间光通信系统采用的光源多为1.55μm半导体激光器,经掺铒光纤放大器后发射功率最高5W左右,限制了空间传输距离,激光发射角不可调,依靠机械式跟瞄系统。激光相控阵作为一种新兴的相干合成技术,采用阵列结构可以增加输出光的能量,控制合成光相位可以实现发射光束角度扫描,提高了动态目标捕获速度。激光相控阵应用于空间激光通信系统,可以大大改善系统性能,实现超远距离高速传输、快速捕获跟踪,成为最有前景的激光通信技术,具有重要的研究意义。本文首先介绍了相控阵以及空间光通信的研究进展,然后讲述了相控阵的基本原理和通信的相关知识。主要介绍了通信系统的组成,包括光发射机、光接收机、光学天线和跟瞄系统,光发射机由种子源和调制器组成,将待传输的信号通过调制器加载到种子源发出的光载波上,经过光学天线发射到大气信道中。光接收机由光探测器和信号处理设备组成。对系统中的调制器、探测器和光学天线的工作原理进行了研究,并且设计了基本的1.06μm空间激光通信系统,实现了高速通信,调制速率最高为10Gb/s,调制方式为强度调制,空间传输距离为2m。研究了以光纤激光相控阵作为种子源的空间激光通信系统,设计了相控阵空间通信系统,采用强度调制,调制速率分别为53Mb/s、120Mb/s、155Mb/s,传输距离为2m,通过实验验证了相控阵空间激光通信的可信性。进行了相控阵种子源和单路调制实验,对比在种子源处调制和在相控阵多条支路中的一路调制两种方式,根据得到的波形图和眼图分析,得出在相控阵种子源处调制是比较合适的调制方式。设计了相控阵多载波调制实验,在相控阵多支路中的两路同时增加强度调制,经过相位控制后,在接收端得到明显的频谱图,最小频率差为0.08MHz,最大频差为20MHz,说明了相控阵能够实现多载波调制,证明了相控阵在空间通信中的应用前景。
[Abstract]:At present, 1.55 渭 m semiconductor lasers are mostly used in free-space optical communication systems. The maximum power of transmission is about 5W after erbium-doped fiber amplifiers, which limits the distance of space transmission, and the laser emission angle is not adjustable. It relies on mechanical tracking and pointing system.As a new coherent combination technique, laser phased array can increase the energy of output light by using array structure, and control the phase of composite light to realize angle scanning of emitting beam and improve the acquisition speed of dynamic target.The application of laser phased array in space laser communication system can greatly improve the performance of the system, achieve ultra-long distance and high-speed transmission, fast acquisition and tracking, and become the most promising laser communication technology, which has important research significance.This paper first introduces the research progress of phased array and space optical communication, then describes the basic principle of phased array and related knowledge of communication.This paper mainly introduces the composition of communication system, including optical transmitter, optical receiver, optical antenna and tracking system. The optical transmitter is composed of seed source and modulator. The signal to be transmitted is loaded into the optical carrier from seed source through modulator.It is transmitted through an optical antenna into the atmospheric channel.The optical receiver consists of a photodetector and a signal processing device.The principle of modulator, detector and optical antenna in the system is studied, and the basic 1.06 渭 m space laser communication system is designed. The high speed communication is realized, the modulation rate is up to 10 GB / s, and the modulation mode is intensity modulation.The space transmission distance is 2 m.The space laser communication system with fiber laser phased array as seed source is studied. The space communication system of phased array is designed and the intensity modulation is adopted.The modulation rate is 53 Mb / s and the transmission distance is 2 m. The credibility of phased array space laser communication is verified by experiments.The experiments of seed source and single channel modulation of phased array are carried out. The modulation at seed source is compared with that in multiple branches of phased array. According to the obtained waveform and eye diagram,It is concluded that modulation at the seed source of phased array is a more suitable modulation method.The experiment of multi-carrier modulation of phased array is designed. The intensity modulation is increased simultaneously in two channels of multi-branch of phased array. After phase control, the obvious spectrum is obtained at the receiving end.The minimum frequency difference is 0.08 MHz and the maximum frequency difference is 20 MHz, which shows that the phased array can realize multicarrier modulation and proves the application prospect of phased array in space communication.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.1

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