极大望远镜高效率多通道光谱仪的光学系统设计

Optical System Design of High Throughput Multi-Channel Spectrograph for Very Large Telescope

建立了基于边界限制的宽波段高效率多通道光谱仪快速设计的分析模型,讨论了多通道光谱仪的性能要求、初始结构参数、项目成本、风险之间的相互关系。该模型能够根据给定的系统指标快速计算出多通道光谱仪各子系统的结构参数,能在项目初期对方案的可行性和项目预算给出合理的评估。以4 m级望远镜为平台,设计了基于体位全息光栅的多通道光谱仪,光谱范围为350～1000 nm,每个通道在闪耀波长处的分辨率为5000,光谱仪本体峰值效率大于53%,全工作波段单色像质能量集中度在80%处优于15μm,满足系统的性能要求。

An analysis model based on boundary limits for multi-channel spectrograph with the broad band and high throughput is built.The relationships among performance requirements,initial parameters,project budget,and risk of the multi-channel spectrograph are discussed.The mathematic model can get structural parameters of each sub-system of the multi-channel spectrograph quickly according to the given system requirements.It also provide a valuable method to evaluate the feasibility of the design and cost budget reasonably at the beginning of the project.A multi-channel spectrograph based on volume phase holographic gratings is designed for the 4 m telescope.It has a wavelength range from 350 nm to 1000 nm and resolution of 5000 at the blazed wavelength in each channel.The peak efficiency of the whole spectrograph is over 53%,and the monochromatic enclosed energy at 80%is better than 15μm with the whole working band,which meets the requirements of system performance.