一种大口径光学望远镜高光谱分辨新技术的研究

High resolution spectral observation on large optical telescope is the foundation of some astrophysical research, which includes searching the first generation star and Earth-like Exoplanet, study on Exoplanet characteristics, study on inter-galactic chemical abundance and so on. Traditional image slicing technology is widely applied in high resolution spectrographs on some large optical telescopes, but still can’t avoid its disadvantage of image irregularity. This proposal studies on a new high resolution spectral technology with pupil-slicing method. The technology doesn't only really enhance the instrument resolution power, but also give good intensity distribution on detector so that satisfies with the requirement on high precision spectral data reduction. On the other hand, the proposal studies on the development of pre-slit pupil-slicing system with concern on manufacture. It includes two modules, respectively beam-shaping module and pupil slicer. And then a pupil-slicing experimental system will be built in order to verify the study result. This proposal can reserve the relative technical force for the planned Chinese large aperture optical telescope since it is very interested in high resolution spectrograph, and serve to most of the present high resolution spectrographs. Therefore, this study has bright future in application.

大口径光学望远镜实现高分辨率光谱观测是第一代恒星和类地行星搜寻、太阳系外行星属性研究、星系际介质丰度研究等天文物理学领域的基础。传统像切分技术在大口径望远镜高分辨率光谱仪上应用广泛，但存在像斑不规则的自身缺陷。本项目研究基于瞳切分的高光谱分辨新技术，实质上提高光谱仪的仪器分辨本领，且像斑保持良好的光强分布，满足高精度光谱处理要求。同时结合制造工艺研究相应的缝前瞳切分系统研制方法，包括光束整形和瞳切分器两个模块，计划建立技术实验平台来验证研究成果。我国计划建设的大口径光学望远镜对高分辨率光谱仪有着极大的兴趣，本项研究可为其储备技术力量，也可服务于现有所有高分辨率光谱仪，应用前景光明。

在大口径光学望远镜上开展高精度高分辨率光谱观测，是推进第一代恒星和类地行星搜寻、精细刻画行星大气、揭秘化学丰度奇异星等天文物理学前沿研究的重要手段。国际上，像切分器结构紧凑，已在大口径望远镜高分辨率光谱仪上广泛应用，可兼顾光谱分辨率和星光利用率，但其存在切分像斑不规则、切分效果易受环境影响等自身缺陷。基于上述科学需求和技术状况，本项目开展了基于光瞳切分的高光谱分辨新技术研究，旨在提高光谱分辨率，同时使切分像斑保持规则的光强分布，提升器件抵御环境变化的能力。主要工作分为四个步骤：（1）研究器件的工作原理和结构类型；（2）完成样机与实验平台的设计；（3）研究核心光学元件的制造工艺，试制样机；（4）测试光瞳切分器样机的光学性能。经测试，样机具备双光纤双光瞳切分的设计功能，验证了光束整形、光瞳切分、像斑重列与指向校准的技术环节，基本掌握了光瞳切分器的光学设计与加工工艺。这项研究成果应用前景光明，将应用于研制中的西班牙GTC高分辨率超稳定光谱仪、我国未来的大口径光学望远镜建设计划，也为2-4米级望远镜高分辨率光谱仪的更新换代提供更多技术选择。