摘要
[目的]相干光通信是一种高速、高质量和高保密的通信方式,而相干检测在相干光通信中有着极其重要的作用.高灵敏度的相干检测系统可以大幅提升相干光通信的距离,通过研究影响相干检测灵敏度的因素可以针对性地做出校正,从而提高检测的灵敏度.[方法]文章简要阐述了相干检测的原理,总结了该领域的国内外研究进展,分析了无线光相干检测系统产生的热噪声、散粒噪声、波前畸变、偏振失配角、光斑尺寸偏差和光轴偏转、耦合效率、探测器的性能和前置光放大器等方面对相干检测灵敏度的影响.[结果]结果表明,系统的热噪声和散粒噪声对检测灵敏度的影响可以通过控制本振光功率使其达到最小;信号光的波前畸变可以通过增加自适应校正系统来抑制;信号光与本振光的偏振失配角可以采用偏振控制补偿装置来补偿;光斑尺寸偏差和光轴偏转需要提高硬件的加工水平来减小这种误差;使用新型的探测器可以在一定程度上提升探测器的性能;前置光放大器能够对微弱的信号光进行放大,对提升检测灵敏度十分重要.[结论]文章分析了影响无线光相干检测灵敏度的因素,总结了近年来国内外学者提高检测灵敏度的方法,为实际应用中检测系统灵敏度的提升提供了理论参考,对相干光通信系统性能的提升有着重要的意义.
Abstract
[Objective]Coherent optical communication is a high-speed,high-quality,and highly secure communication method,and coherent detection plays an extremely important role in coherent optical communication.High sensitivity coherent detection systems can significantly increase the distance of coherent optical communication.By studying the factors that affect the sensi-tivity of coherent detection,targeted corrections can be made to improve the detection sensitivity.[Methods]This paper first briefly describes the principle of the coherence detection,and summarizes the research progress in this field at home and a-broad.Then the paper analyzes the influence of thermal noise,shot noise,wavefront distortion,polarization loss,spot size de-viation,optical axis deflection,coupling efficiency,detector performance,preamplifier and other aspects on coherence detection sensitivity of wireless optical coherence detection system.[Results]The results show that the influence of the thermal noise and shot noise of the system on the detection sensitivity can be minimized by controlling the local oscillator power.The wavefront distortion of signal light can be suppressed by adding an adaptive correction system.The polarization control compensation de-vice can be used to compensate the polarization mismatch between signal light and local oscillator light.The deviation of spot size and optical axis deviation requires improving the processing level of hardware to reduce this error.The use of new detectors can improve the performance of detectors to a certain extent.The pre-amplifier can amplify weak signal light,which is crucial for improving detection sensitivity.[Conclusion]This article analyzes the factors that affect the sensitivity of wireless optical coherent detection,and summarizes the methods used by domestic and foreign scholars to improve detection sensitivity in re-cent years.It provides theoretical reference for improving the sensitivity of detection systems in practice,which has important significance for improving the performance of coherent optical communication systems.
基金项目
陕西省教育厅科研计划资助项目(18JK0341)
陕西省重点产业创新资助项目(2017ZDCXL-GY-06-01)
西安市科技计划资助项目(2020KJRC0083)
维普
万方数据