Appl Opt. 2023 Apr 20;62(12):3004-3015. doi: 10.1364/AO.484192.
The paper presents a method for calculation of the main paraxial and energy parameters of a high-resolution astronomical spectrograph with a single echelle grating in a wide spectral range, without cross-dispersion elements. We consider two variants of the system design, namely, with a fixed grating (spectrograph) and with a movable grating (monochromator). Based on the analysis of the spectral resolution dependence on the echelle grating characteristics and the collimated beam diameter, the limits of the achievable maximum spectral resolution of the system are determined. The results obtained in this work can simplify the choice of the starting point for spectrograph designing. As an example of the presented method application design of the spectrograph for the Large Solar Telescope-coronagraph LST-3, operating in the spectral range of 390-900 nm, with spectral resolving power of =200,000 and minimum diffraction efficiency of the echelle grating >0.68, is considered.
本文提出了一种在宽光谱范围内无需色散元件的单阶梯光栅高分辨率天文摄谱仪的主傍轴和能量参数的计算方法。我们考虑了两种系统设计方案，即固定光栅（摄谱仪）和可动光栅（单色仪）。基于对光谱分辨率与阶梯光栅特性和准直光束直径的依赖关系的分析，确定了系统可实现的最大光谱分辨率的限制。这项工作的结果可以简化摄谱仪设计的起点选择。作为所提出方法应用的一个例子，设计了在光谱范围为 390-900nm 下工作的大太阳望远镜-日冕仪 LST-3 的摄谱仪，光谱分辨率为 =200,000，阶梯光栅的最小衍射效率 >0.68。
