基于棱锥波前传感器的多镜面望远镜系统波前探测和共相技术研究

This project aims at the future development of telescope technology with large aperture, and focuses on the pyramid wavefront sensor used in the turbulence wavefront sensing and co-phasing of the multiple mirror telescope system, and establishes a laboratory demonstration platform based on the pyramid wavefront technology of the multiple mirror telescope. The theory reconstruction model of the pyramid wavefront detection for the non-continuous turbulence wavefront will be derived, and the co-phasing detection based on the pyramid interference signal will be analyzed, and the technical scheme of signal separation and extraction will be analyzed according to the reconstruction algorithm. The dynamic characteristics of turbulence, and the influence mechanism and influence degree of various noise sources on the detection performance of the system are analyzed. The simulation data of multiple mirror telescope error detection and correction based on pyramid wavefront sensor under different initial conditions are obtained through numerical simulation with optical software. The change rules of various parameters are summarized, and the control model and control algorithm are established. The experimental platform of error detection and correction for multiple mirror telescope system based on the pyramid wavefront sensor will be set up, and the experimental demonstration of the key technology will be realized. Through theoretical deduction, simulation analysis and experimental demonstration, the physical essence and control rule of this technology will be obtained, and the necessary knowledge reserve and technical verification will be provided for the development of the telescope with large aperture.

本申请项目瞄准未来大口径望远镜技术发展需求，旨在研究棱锥波前传感器在多镜面式望远镜系统中湍流波前误差探测和共相误差探测的技术应用，并建立基于该技术的新型多镜面望远镜自适应光学探测与校正室内实验论证平台。课题推导多镜面整体非连续湍流波前的棱锥探测重构算法，分析多镜面共相误差与棱锥干涉信号之间的内在联系，建立误差耦合信号的分离和提取技术方案；剖析湍流动态特征、各种噪声源对系统探测性能的影响机理和影响程度；利用光学软件进行数值仿真，获取不同初始条件和误差影响下基于棱锥波前传感器的多镜面望远镜误差探测与校正仿真数据，总结各种参数影响的变化规律，建立系统控制模型和控制算法；搭建基于棱锥波前传感器的多镜面望远镜系统误差探测与校正实验平台，实现对该关键技术的实验论证。通过理论推导、仿真分析和实验论证，揭示该技术的物理本质和控制规律，为我国下一代大口径多镜面式望远镜的研制提供必要知识储备和先期技术验证。

由于镜面材料制备、光学加工检测、制造费用昂贵等限制因素，传统的单孔径成像望远镜已经很难适应现代天文学的发展需求。基于多镜面技术的望远镜系统，采用几个口径比较大的分离子镜来共同构成超大口径的光学主镜面，是一种非常有前途的大口径望远镜实现技术。为了实现多镜面成像系统的高分辨观测能力，必须要对分离主镜的整体非连续波前、以及各子孔径之间的共相误差进行探测。本项目瞄准基于棱锥波前传感器的多镜面式望远镜系统波前探测与共相的关键技术开展研究，通过理论推导和仿真分析，建立了棱锥探测信号与非连续整体波前的模式重构方案，并且分析了棱锥干涉区域内信号与共相误差之间的内在联系，同时搭建了光学实验平台，利用棱锥波前传感器进行误差探测，同时采用液晶空间光调制器和拼接能动反射镜等器件，通过闭环控制对误差的补偿校正，从而实现了对棱锥波前传感器关键技术应用的室内平台验证。