伪随机序列调制的激光外差探测  

Pseudo-random frequency modulated laser heterodyne detection

作　　者：刘立生[1,2,3] 赵帅[1,2,3] 郭劲[1,2] 

机构地区：[1]激光与物质相互作用国家重点实验室,吉林长春130033 [2]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [3]中国科学院研究生院,北京100049

出　　处：《红外与激光工程》2011年第10期1890-1895,共6页Infrared and Laser Engineering

基　　金：中国科学院三期创新项目(O98Y32C100)

摘　　要：在激光外差探测中,为了增强在频谱密度上对多普勒频移峰值的识别能力,提升对目标的探测概率,提出一种采用伪随机序列对连续激光进行调制的外差探测方法。应用伪随机序列的M序列码对发射激光和本振光同时进行频率调制,接收信号光和经时间延迟后的本振光相干叠加形成拍频信号。其特点是二进制码调制同时作用于发射信号光和本振光,使外差信号频谱上同时出现3个峰值,减小了外差探测时的虚警率,提高了探测的信噪比。通过模拟仿真计算,证明了此探测模型有着良好的抗干扰能力和较好的噪声滤除能力。In order to enhance the capability to identify the peak value in the power spectrum density （PSD） of the laser heterodyne signal, and improve the detection probability, a new laser heterodyne detection method, in which pseudo-random frequency modulation was conducted on the continuous wave laser, was proposed. Pseudo-random M sequence frequency modulation was carried out to modulate both the transmitted beam and the local beam. The mixing of the received signal beam and the time-delayed local beam formed the beat signal. The feature of this method was modulation of the transmitted beam and the local beam simultaneously with pseudo-random sequence, resulting 3 peak values in the PSD of the heterodyne signal, which reduced false alarm and raised signal-to-noise ratio obviously. A good performance of anti-jamming capability and noise-filtering capability was proved through simulation of this detection model.

关 键 词：激光雷达 外差探测 伪随机序列 快速傅里叶变换 

分 类 号：TN24[电子电信—物理电子学]