光斑均匀化在声光偏转相干探测系统的应用研究

Study on beam uniformity for the coherent optical detection system based on acousto- optic deflection

针对声光偏转效应相干探测系统信号光斑随射频信号变化的偏移特性,利用光斑重叠物理模型,研究光斑结构与混频效率的关系,分析光轴偏移、探测器有效光敏面半径以及本振光能量匹配等因素对相干光探测效率的影响。计算机仿真和实验测试验证表明,以能量分布均匀光斑作为本振光斑,有利于在一定范围内漂移的信号光与参考光重叠相干混频效率改善,当信号光偏移量±0.5 mm内,重叠效率下降不到5%,通过光斑结构及能量分布的研究,为后续实际应用提供参考依据。

For signal light spot based on the acousto-optic deflection with RF signal changing in the coherent optical detection system,the relationship between spots structure and mixing efficiency is studied by using spots overlapping physical model,effects of optical axis deviation,active photosensitive surface radius,and local oscillator energy match are analyzed on coherent detection efficiency. The computer simulation and experiment test show that,using uniform energy distribution spots as local oscillator,this is very helpful for coherent mixing efficiency improvement within a certain range drift of signal light spot,when the signal light axis deviation is in the range- 0. 5 ~ 0. 5mm,the overlapping efficiency declines only by less than 5%. Through study of energy distribution and spots structure,the basis reference for subsequent applications can be provided.