在空间目标探测中, 由于远距离、小目标的特点, 回波信号十分微弱, 传统的激光雷达不能很好地探测如此微弱的信号。而且现在空间目标探测不仅需要距离信息, 还希望获得目标的强度、偏振等更加多维的信息。提出了基于Gm-APD单光子灵敏度探测器的四路光子偏振探测系统, 以Gm-APD探测器的泊松概率响应模型为基础, 推导了回波微弱信号的强度解算公式, 通过四路的强度解算出回波信号的偏振信息, 在实验室搭建了四路Gm-APD光子偏振探测系统的原理样机, 并介绍了四路Gm-APD光子斯托克斯参量的探测实验。在平均每个脉冲回波能量为7.78×10-19 J的情况下, 获得3.95%的线偏振误差和5.84%的椭圆偏振误差的探测结果。

In the application of space target detection, due to the characteristics of small target and great distance, the returned signal is very weak, even a few of photons or less than a photon per pulse. Such weak signal can't be detected by traditional laser radar. Moreover, the space target detection now not only needs the range information, but hopes to get the intensity, polarization and more multi-dimensional information. Therefore, high sensitivity photon polarization laser radar system was proposed based on the four-way Gm-APD single photon detector. The intensity formula of weak signal was deduced from the Poisson probability model of Gm-APD detector. Then, the polarization information of the returned signal was obtained through four-way intensity results. Finally, the principle prototype of four-way Gm-APD photon polarization laser radar system was established in the laboratory, and the relevant experiment was conducted. When the average energy of returned signal per pulse is 7.78×10-19 J, the experimental results show the linear polarization error of 3.95% and the elliptical polarization error of 5.84%.