[Study on the Design of Prism Hyperspectral Imaging System Based on Off-Axis Two-Mirror Littrow Configuration]

In order to meet the requirements of high spectral resolution and high image quality on the hyperspectral imaging system, and to meet the new demands of miniaturization, light weight, and high optical efficiency in practical applications, a prism known as hyperspectral imaging system based on Littrow configuration is designed. The use of off-axis two-mirror Littrow configuration is to reduce the size of the optical system and provide a collimated beam for the plane prisms. To avoid the optical path interference, the macro programming optimization is applied. The application of two correct lens and aspheric mirrors can correct the spectral smile and the keystone of the hyperspectral imaging system. It is indicated that the distortion is less than 2.1 μm and the spectral bend is less than 1.3 μm, both are controlled within 18% pixel. The analytical results indicate that the MTF in the visible-near infrared(VNIR) spectral region from 400 to 1 080 nm is above 0.9 while spectrum resolution is about 1.6～5.0 nm, the spectral transmittance more than 51.5%. The results show that the system has high transmittance and image quality within the whole spectral range.