交叉非对称型Czerny-Turner光谱仪光学系统设计

根据Czerny-Turner结构光谱仪工作原理,以便携式微型光学系统为设计目标,设计了一种光谱范围为200900nm的交叉非对称型Czerny-Turner光谱仪光学系统.通过分辨率、光谱范围等设计要求确定光谱仪大致结构后,引入初级像差对初始结构进行进一步优化.首次提出将球差约束条件与光阑面选取相结合,设计流程确定准直镜通光口径、光栅初始尺寸及聚焦镜中心波长对应口径,继而结合彗差约束条件,确定球面镜离轴角,并基于几何光学确定聚焦镜初始通光口径的方法.利用ZEMAX软件对初始参量进行模拟优化,并采用自主研制的样机进行光谱测量,分析结果表明,该光学系统能够在狭缝宽度为25μm,光栅常数为1.667μm/line条件下,实现中心波长分辨率优于1nm,边缘波长分辨率优于1.5nm.

Design of Crossed-asymmetric Czerny-Turner Spectrometer Optical System

According to the working principle of Czerny-Turner structure spectrometer, to make the system miniature and portable as specific design objectives, a crossed-asymmetric Czerny-Turner spectrometer with spectral range of 200 nm~900 nm was designed.Based on the spectrometer resolution and spectral range, we could determine the general structure.Then the primary aberration was used to optimize the initial structure, first proposed combining the spherical aberration constraints and aperture surface selection and designed process to determine the collimating mirror aperture, initial grating size and focusing lens aperture of the center wavelength, and then combined with the constraints of coma to calculate the spherical mirror off-axis angle, and based on geometric optics to determine the initial focus lens aperture.The imaging simulation, analysis and optimization for optical system were carried out with optical design program ZEMAX.The spectrum of mercury-argon light and the spectrum of halogen light are measured by our self-developed spectrometer.The results of analysis demonstrated that the optical system achieved central wavelength resolution less than 1 nm, edge wavelength resolution less than 1.5 nm, in conditions of the slit width is 25 μm, the groove spacing is 1.667 μm/line.