双罗兰圆结构光谱仪的光学系统设计

提出一种基于双罗兰圆光学结构的光谱仪光学系统及其设计方法。其中，200 nm～500 nm光路为常规的罗兰圆光学结构；500 nm～700 nm光路运用凹面光栅第零衍射级次光谱线，利用平面反光镜将谱线射入另一个凹面光栅，实现了双罗兰圆光学结构。根据设计要求及光学系统各个参数之间的相互约束，设计、计算出光学系统各个参数指标，基于Zemax仿真分析，调整光学参数并验证光学系统的可行性。针对平面信号探测器在罗兰圆周上存在像差问题，利用反光镜增添信号探测器的可摆放个数，使像差比初始结构减小4.475 μm，光谱仪整体光学结构尺寸小于400 mm × 500 mm。仿真结果表明:光谱仪所测的光谱波段范围可达200 nm～700 nm，全波段分辨率达0.4 nm。

Optical system design of spectrometer with double Rowland circle structure

An optical system of a spectrometer based on the double Rowland circle optical structure and its related design methods were proposed. The optical path in the detection wavelength range of 200 nm~500 nm was a conventional Rowland circle optical structure. The optical path in the detection wavelength range of 500 nm~700 nm used the zeroth diffraction?order subspectral lines diffracted by a concave grating, which were adjusted by a plane reflector to project the spectral lines into another concave grating, and the double Rowland circle optical structure was realized. According to the design requirements and the mutual constraints among the various parameters of the optical system, the various parameters were designed and calculated. Based on Zemax simulation analysis, the optical parameters were adjusted and the feasibility of the optical system was verified. Aiming at the problem of aberration of the planar signal detector on the Rowland circle, the reflector was used to increase the number of signal detectors, and the aberration was reduced by 4.475 μm compared with that of initial structure. The overall optical structure size of the spectrometer was less than 400 mm 500 mm. Simulation results show that the spectral band range measured by the spectrometer can reach 200 nm~700 nm, and the whole band resolution can reach 0.4 nm.