基于电子倍增电荷耦合器件的哈特曼-夏克波前传感器质心探测误差分析

哈特曼-夏克(Hartmann-Shack,H-S)波前传感器的探测误差是自适应光学系统中的一个主要误差源.本文分析了电子倍增电荷耦合器件(electron multiplying charge-coupled devices,EMCCD)的各种噪声源对H-S波前传感器质心探测误差的影响,推导了基于EMCCD的H-S波前传感器的质心探测误差的数学表达式,并进行了数值仿真和实验研究.结果表明,基于EMCCD的H-S波前传感器的质心探测误差与增益直接相关,在增益小于P_max/(Q·N_mean)时质心探测误差随着增益的增大而减小,在增益大于P_max/(Q·N_mean)时质心探测误差随着增益的增大而增大,其中P_max是EMCCD的峰值电荷,Q是量子效率,N_mean是平均入射光强.关键词：自适应光学电子倍增电荷耦合器件波前传感器质心探测误差

The detection error analysis of Hartmann-Shack wavefront sensor based on electron multiplying charge-coupled devices

The detection error of Hartmann-Shack (H-S) wavefront sensor is one of the main errors in adaptive optical systems. In this paper, the detection error of H-S wavefront sensor based on the electron multiplying charge-coupled devices (EMCCD) is firstly analyzed and the detection error formula is established. Furthermore, the numerical simulation and experimental results show that the centroid detection error is related to the gain of EMCCD. The centroid detection error decreases with gain increasing when the gain is lower than P_max/(Q·N_mean). When the gain is higher than P_max/(Q·N_mean), the centroid detection error increases with the gain increasing, where P_max is the peak electric charge value of EMCCD, Q is quantum efficiency, N_mean is the mean number of incident photons.