Zhang Xuan, Wang Jian, Zhang Jun, Yan Jie, Han Yan
Opt Express. 2022 Oct 10;30(21):38266-38283. doi: 10.1364/OE.465523.
A spectrometer design method based on the prism-prism-grating (PPG) dispersion module is proposed in this paper to correct the serious nonlinear dispersion that prism and grating spectrometers and other dispersive spectrometers suffer from. First, we determine the criteria for selecting the optical materials of the PPG module by analyzing the dispersion characteristics of prisms and gratings. Second, a loop traversal algorithm is used to optimize the system structure parameters after selecting optical materials. Next, the direct vision coaxial condition of the PPG module is derived according to basic optical principles and the geometrical relationship between optical elements. Then, the dispersion equation of the PPG module is used to establish the spectral linearity index of the system. Finally, combined with the design index, the structural parameters of the PPG module to meet the linear dispersion requirements are determined. A direct vision coaxial linear dispersion spectrometer is designed and realized under the condition that the working band is 400-990 nm, the deviation angle and offset of the emitted ray with a central wavelength of 695 nm with respect to the optical axis are 0, and the dispersion angle is not less than 15°. The results simulated by ZEMAX show that the actual simulation results are consistent with the theoretical calculation results, the spectral resolution of the spectrometer is less than 1.5 nm, and the spectral smile and keystone are less than 3.89% pixels. In the discussion section, the influences of the dispersion ability of optical materials and the incident angles of prisms and gratings on the spectral dispersion linearity of the PPG module are analyzed and studied. The universality of the spectrometer design method developed in this paper is discussed, and its universality is simulated and verified in the 1000-1600 nm and 1600-2200 nm bands. In addition, some advantages compared with other dispersion structures are analyzed.
本文提出了一种基于棱镜-棱镜-光栅（PPG）色散模块的光谱仪设计方法，以校正棱镜和光栅光谱仪等色散光谱仪所面临的严重非线性色散问题。首先，通过分析棱镜和光栅的色散特性，确定PPG模块光学材料的选择标准。其次，在选择光学材料后，采用循环遍历算法优化系统结构参数。接着，根据基本光学原理和光学元件之间的几何关系，推导PPG模块的直视同轴条件。然后，利用PPG模块的色散方程建立系统的光谱线性指标。最后，结合设计指标，确定满足线性色散要求的PPG模块结构参数。设计并实现了一种直视同轴线性色散光谱仪，其工作波段为400 - 990 nm，中心波长为695 nm的出射光线相对于光轴的偏角和偏移量为0，色散角不小于15°。ZEMAX模拟结果表明，实际模拟结果与理论计算结果一致，光谱仪的光谱分辨率小于1.5 nm，光谱微笑和梯形畸变小于3.89%像素。在讨论部分，分析研究了光学材料的色散能力以及棱镜和光栅的入射角对PPG模块光谱色散线性的影响。讨论了本文所开发的光谱仪设计方法的通用性，并在1000 - 1600 nm和1600 - 2200 nm波段对其通用性进行了模拟验证。此外，还分析了与其他色散结构相比的一些优势。
