Huang Linshu, Wang Jianli, Chen Lu, Yuan Hangfei, Li Hongzhuang, Yao Kainan
Opt Express. 2022 Mar 28;30(7):10833-10849. doi: 10.1364/OE.449021.
Daytime application of the pyramid wavefront sensor (PyWFS) is greatly challenged by a bright and fluctuating sky background, especially in the visible. A daytime-Py approach to apply visible pyramid wavefront sensing for real-time daylight AO is described in this paper. A field stop (FS) and a lenslet array are applied in the daylight AO system based on a visible PyWFS to separate the object signal from the background signal and improve the signal-to-noise ratio (SNR). A background elimination algorithm is proposed to extract the effective object signal. Closed-loop experiment using the daytime-Py approach is performed, which presents the first laboratory real-time daylight natural guide star AO correction of a faint object based on a visible PyWFS. SNR ranges for both the daytime-Py approach and PyWFS are reported. Furthermore, the correction results in different SNRs using both methods and with various pupil samplings using the daytime-Py approach are presented to prove that our proposal has the advantages over the PyWFS and Shack-Hartmann wavefront sensor (SHWFS) for daylight AO. This study demonstrates that the daytime-Py approach can realize the real-time object tracking and closed-loop correction in the daylight natural guide star adaptive optics (AO) system based on the visible PyWFS.
金字塔波前传感器（PyWFS）的日间应用受到明亮且波动的天空背景的极大挑战，尤其是在可见光波段。本文描述了一种日间Py方法，用于将可见金字塔波前传感应用于实时日光自适应光学（AO）。在基于可见PyWFS的日光AO系统中应用了一个视场光阑（FS）和一个微透镜阵列，以将目标信号与背景信号分离并提高信噪比（SNR）。提出了一种背景消除算法来提取有效的目标信号。进行了使用日间Py方法的闭环实验，该实验展示了基于可见PyWFS的首个实验室实时日光自然导星AO对微弱目标的校正。报告了日间Py方法和PyWFS的SNR范围。此外，还给出了使用这两种方法在不同SNR下以及使用日间Py方法在不同瞳孔采样下的校正结果，以证明我们的方案在日光AO方面比PyWFS和夏克 - 哈特曼波前传感器（SHWFS）具有优势。本研究表明，日间Py方法能够在基于可见PyWFS的日光自然导星自适应光学（AO）系统中实现实时目标跟踪和闭环校正。
