凹面光栅拉曼光谱仪的光学设计

Optical Design of Concave Grating Raman Spectrometer

在传统Czerny-Turner光谱仪结构的基础上，设计了基于凹面光栅和球面聚焦反射镜结构的便携式拉曼光谱仪。在子午面内利用凹面光栅像差理论得到了消初级彗差公式，并结合几何关系，得出了像面大小和系统参数的关系式。以532nm的激光作为激发光源，物方数值孔径为0．12，探测器选用1024pixel×64pixel的电荷耦合器件（CCD），其中像元合并使用变成了一个线阵CCD。利用Zemax软件对设计结果进行模拟和分析，得到了一个在537-615nm波长范围内均能实现0．3nm光谱分辨率的紧凑结构。在Zemax软件非序列模式下对像面进行分析，整个波段都在CCD接收范围内，证明了该结构的可行性。

Portable Raman spectrometer is designed with concave grating and spherical mirror on basis of classic Czerny-Turner spectrometer in this paper. The equation of primary coma-free is concluded according to aberration theory of concave grating. Combined with geometrical relationship in tangential plane, the relation of size of image plane and parameter of this system is concluded. Laser of 532 nm is selected asexcitation light source with object numerical aperture （NA） of 0.12. Charge-coupled device （CCD） with 1024 pixel×64 pixel is selected as detector, in which 64 pixels is combined to make a linear array CCD. This design is simulated and analyzed by Zemax, and spectral resolution of 0.3 nm is realized at the band from 537 nm to 615 nm with a portable institutions. Image plane is analyzed in Zemax non-sequential mode. The whole band is in the receiving range of CCD, which proves the feasibility of this structure.