论文标题
Harmoni Pyramid WFS模块的设计
Design of the HARMONI Pyramid WFS module
论文作者
论文摘要
当前三个极大的望远镜的当前设计表明，金字塔波前传感器（P-WFS）作为自适应光学器件（AO）系统对天然导向星（NGS）或扩展对象的感觉的压倒性采用。 P-WFS比Shack-Hartmann的关键优势是已知的，并且主要是由提高灵敏度（Fainter ngs）和对空间混叠的敏感性降低提供的。但是，当前对P-WFS对ELT的稳健性和公差目前尚不清楚。在本文中，我们介绍了Harmoni的单相轭AO模式的模拟结果，Harmoni是欧洲极大望远镜的可见且近红外的积分光谱仪。我们首先探索与望远镜本身有关的波前传感问题。即岛的效应（即差异活塞）和M1段阶段错误。我们为岛屿效应及其性能提出了缓解策略。然后，我们专注于AO设计的一些性能优化方面，以探索RTC潜伏期和光学增益问题的影响，这特别会影响Harmoni的高对比度模式。最后，我们研究了玻璃金字塔棱镜本身的质量以及对最终AO性能的光学畸变的影响。通过放松对棱镜制造的公差，我们能够降低硬件成本并简化集成。我们显示了校准的重要性（即更新控制矩阵）捕获望远镜学生的任何位移以及M4支撑结构的旋转。我们还显示了用于波前传感的像素数量的重要性，以放松金字塔棱镜的公差。最后，我们提出了PYRAMID PRISM的详细光学设计，这是P-WFS的中心元素。
Current designs for all three extremely large telescopes show the overwhelming adoption of the pyramid wavefront sensor (P-WFS) as the WFS of choice for adaptive optics (AO) systems sensing on natural guide stars (NGS) or extended objects. The key advantages of the P-WFS over the Shack-Hartmann are known and are mainly provided by the improved sensitivity (fainter NGS) and reduced sensitivity to spatial aliasing. However, robustness and tolerances of the P-WFS for the ELTs are not currently well understood. In this paper, we present simulation results for the single-conjugate AO mode of HARMONI, a visible and near-infrared integral field spectrograph for the European Extremely Large Telescope. We first explore the wavefront sensing issues related to the telescope itself; namely the island effect (i.e. differential piston) and M1 segments phasing errors. We present mitigation strategies to the island effect and their performance. We then focus on some performance optimisation aspects of the AO design to explore the impact of the RTC latency and the optical gain issues, which will in particular affect the high-contrast mode of HARMONI. Finally, we investigate the influence of the quality of glass pyramid prism itself, and of optical aberrations on the final AO performance. By relaxing the tolerances on the fabrication of the prism, we are able to reduce hardware costs and simplify integration. We show the importance of calibration (i.e. updating the control matrix) to capture any displacement of the telescope pupil and rotation of the support structure for M4. We also show the importance of the number of pixels used for wavefront sensing to relax tolerances of the pyramid prism. Finally, we present a detailed optical design of the pyramid prism, central element of the P-WFS.
