在自由空间激光通信中, 精跟踪单元的探测器经常选用四象限探测器(QD), 探测器的性能影响跟踪精度。为了研究四象限探测器在不同条件下的性能, 提出变步长的方法, 分析光斑大小对动态范围和探测灵敏度的影响情况, 在满足仿真精度的前提下, 缩短了仿真时间。在光斑能量服从高斯分布的情况下, 分析背景光、光电响应度和死区对动态范围和探测灵敏度的影响, 特别研究非均匀背景光的影响。结果表明, 随着光斑半径的增加, 光斑位置检测的动态范围在增大, 位置探测灵敏度在降低。相同光斑半径条件下, 对于服从艾里分布的光斑的位置探测灵敏度高于服从高斯分布的光斑, 而动态范围小于后者, 非均匀背景光对探测器性能的影响比均匀背景的影响大。

Four-quadrant detector (QD) is used for detector of extract track in free space optical communication, and influences tracking precision. The method of the variable step-size is given, and the influences of the facular size to the dynamic range and the detection sensitivity are analyzed. As the simulation precision is satisfied, simulation time is shortened. On the condition that the facular energy obeys the Gauss distribution, the influences of the background light, responsibility and dead-area to the dynamic range and the detection sensitivity are analyzed, especially the influence of the non-uniformity background light is analyzed. The result indicates that the dynamic range of facular position detection is increased, and detection sensitivity is reduced with the increase of the facular size. On the condition of the same facular size, the detection sensitivity as to obey Airy distribution is higher than Gauss distribution, the influence of non-uniformity to the detector is larger than uniformity.