标题： MAORY/MORFEO与激光导星波前感测中的滚动快门引起的像差 显示英文标题

标题： MAORY/MORFEO and rolling shutter induced aberrations in laser guide star wavefront sensing

摘要： 激光导星（LGS）Shack-Hartmann（SH）波前传感器用于下一代极大望远镜（ELTs），需要低噪声、大格式（约1百万像素）、快速读取的探测器，以满足大量子孔径和非常拉长光斑良好采样的需求。为满足这一需求，采用了一种基于CMOS探测器的滚动快门读出方案，它以图像失真为代价，实现了低读出噪声和快速读出时间。本文分析了当这种滚动快门读出方案用于欧洲南方天文台（ESO）极大望远镜观测的多共轭自适应光学中继器（MORFEO，曾称为MAORY）的LGS SH波前探测时的影响；特别是，我们关注了滚动曝光引起的畸变导致的像差对自适应光学校正的影响，特别是在快速变化的像差情况下，例如由激光束上行传播引起的LGS倾斜抖动所导致的像差。我们发现MORFEO的LGS抖动引起的像差最大可达100纳米均方根，并讨论了可能的缓解策略。 显示英文摘要

摘要： Laser Guide Star (LGS) Shack-Hartmann (SH) wavefront sensors for next generation Extremely Large Telescopes (ELTs) require low-noise, large format (about 1Mpx), fast detectors to match the need for a large number of subapertures and a good sampling of the very elongated spots. One path envisaged to fulfill this need has been the adoption of CMOS detectors with a rolling shutter read-out scheme, that allows low read-out noise and fast readout time at the cost of image distortion due to the detector rows exposed in different moments. In this work we analyze the impact of the rolling shutter read-out scheme when used for LGS SH wavefront sensing of the Multiconjugate adaptive Optic Relay For ELT Observations (MORFEO, formerly known as MAORY) for ESO ELT; in particular, we focus on the impact on the adaptive optics correction of the distortion-induced aberrations created by the rolling exposure in the case of fast varying aberrations, like the ones coming from the LGS tilt jitter due to the up-link propagation of laser beams. We show that the LGS jitter-induced aberration for MORFEO can be as large as 100nm rms and we discuss possible mitigation strategies.