Optical structure symmetric imaging spectrometer based on single grating spectroscopy

Aiming at the complex structure of imaging spectrometer and the difficulty of correcting spectral line bending, a high-resolution imaging spectrometer based on a single transmission grating was designed and developed. Firstly, the optical splitting model of a single transmission grating was established, and the design parameters of the optical splitting system were calculated and determined. Among them, the collimation part and the focusing imaging part of the optical splitting system adopted the symmetry optical structure, which was conducive to the correction of aberrations and reduce the cost of the system. In the design process, the spectral resolution was taken as the main goal, and gradually optimized from the focusing system to the whole spectral splitting system. Finally, a set of optical splitting system with slit width of 11.42 μm, working band of 450 nm~650 nm, spectral resolution of 2 nm, F-number of 2.5, the maximum spectral line bending of 19 μm, and the maximum color distortion of 0.35 μm was designed. According to the design results, the fabrication and assembly of the imaging spectrometer were completed. The experimental results show that the spectral resolution of the system is not less than 2 nm, which meets the design requirements, and proves that the imaging effect of the spectrometer is good.