用于白天自适应光学的波前探测方法分析

Analysis of wavefront measuring method for daytime adaptive optics

提出了两种视场偏移哈特曼波前传感器,用于探测白天条件下强背景中目标信号的波前信息.给出了哈特曼波前传感器子孔径中焦面上天光背景非均匀性分布特征的实验结果,详细分析了基于分光棱镜的双焦面视场偏移哈特曼波前传感器的探测误差,并通过基于倾斜镜的单焦面视场偏移哈特曼波前传感器实验给出了波前测量的结果,证明视场偏移哈特曼波前传感器能够精确、稳定的测量白天条件下目标信号的畸变波前信息,同时给出了其在白天条件下探测能力的估算结果及其受限因素,估算结果表明云南天文台的自适应光学系统在10W/m2.sr天光背景条件下应用视场偏移哈特曼波前传感器能对5等星(可视星等值)目标进行准确的波前探测.

Two field-of-view shifted Shack-Hartmann wavefront sensors （FSWFS） are proposed, which are used to measure the wavefront information of object signal under daytime conditons. The experimental results on the sky background＇s non-uniformity characteristics are obtained, the detecting error of the dual focal-plane FSWFS is analyzed in this paper and its principle has been proven by experiments with a single focal-plane array. The measuring results indicate that FSWFS can precisely and stably measure the wavefront information of object signal with strong background. At the same time, the detection capacity of FSWFS is estimated and its restraining factors are analyzed, and the estimation results show that the adaptive optics system with FSWFS in Yunnan observatory can precisely measure the wavefront information of object signal whose V magnitude is 5 when the brightness of the sky background is 10 W/m^2 .sr.