双频激光相干探测差频信号影响因素分析  

Analysis of influencing factors of difference frequency signal of dual frequency laser coherent detection

作　　者：任建迎 孙华燕 赵延仲 张来线 REN Jian-ying;SUN Hua-yan;ZHAO Yan-zhong;ZHANG Lai-xian(Graduate School,Space Engineering University,Beijing 101416,China;Department of Electronic and Optical Engineering,Space Engineering University,Beijing 101416,China)

机构地区：[1]航天工程大学研究生院,北京101416 [2]航天工程大学电子与光学工程系,北京101416

出　　处：《激光与红外》2020年第4期407-412,共6页Laser & Infrared

摘　　要：为实现高速运动目标的低多普勒探测,提出了双频相干激光的差频光探测方法。对双频激光相干产生的差频信号光学影响因素进行了分析。首先,根据干涉理论得到差频光,结合维纳-辛钦定理推导得到了差频光的功率谱函数。然后,利用频域积分法得到差频光信噪比,并对差频光的条纹对比度进行了分析,最后进行了双频激光相干产生差频信号的实验研究。理论分析和实验表明,激光线宽的增大导致差频光信噪比和条纹对比度的下降,光程差越小条纹对比度越好,移频器的频率扰动导致差频光中心频率的波动。In order to realize low Doppler detection of high-speed moving targets,a difference frequency detection method of dual frequency coherent laser is proposed.The optical factors affecting the difference frequency signal generated by the dual-frequency laser coherence are analyzed.Firstly,the power spectrum function of the differential frequency light is derived by using the Wiener-Khinchin theorem.Then,the frequency domain integral method is used to get the difference frequency optical signal to noise ratio,and the fringe contrast of the difference frequency optical signal is analyzed.Finally,the experimental study on the difference frequency signal generated by dual frequency laser coherent mixing is carried out.Theoretical analysis and experiments show that the increase of laser line width leads to the decrease of difference frequency optical signal-to-noise ratio and fringe contrast,and the smaller the difference of optical path,the better the fringe contrast,and the frequency disturbance of frequency shifter leads to the fluctuation of difference frequency optical center frequency.

关 键 词：双频激光 激光线宽 差频光 相干探测 高速目标 

分 类 号：TN249[电子电信—物理电子学]