调制器失调下的大视场猫眼回波特性分析

基于猫眼效应的逆向调制激光通信系统可以实现更快的通信速率,但是在实际应用中系统一般为非理想状态,其中调制器失调对猫眼回波分布有着重要的影响。基于柯林斯衍射积分公式建立了调制器失调下的大视场猫眼回波分布模型,理论分析了调制器俯仰角与入射角的关系以及两者对回波分布的影响规律并进行了实验验证。结果表明:调制器俯仰角和入射角共同影响回波光斑的形状,若两者取值符号相反,可减弱产生的影响。利用这一特性可以增强回波强度,改善猫眼逆向调制通信系统的性能。

Analysis of echo characteristics of large field cat′s eye under modulator misalignment

Modulating retro-reflector laser communication system based on the cat′s eye effect can achieve a faster communication rate,but the system is generally non-ideal in practical applications,wherein the modulator offset has an important influence on the cat′s eye echo distribution.Based on the Collins diffraction integral formula,the large field of view cat′s eye echo distribution model under modulator misalignment is established.The relationship between the pitch angle of the modulator and the incident angle and the influence of the two on the echo distribution are analyzed theoretically and verified experimentally.The results show that the incident angle and the pitch angle of the modulator together affect the shape of the echo spot.In addition,if the sign of the incident angle and the pitch angle of the modulator are opposite,the negative effects of both can be mitigated.This feature can be used to enhance the echo intensity and improve the performance of modulating retro-reflector laser communication system based on the cat′s eye effect.