Abstract:To achieve precise applications under specific environmental requirements, an infrared optical system that can be applied to near-infrared wavelengths was designed. First of all, based on the selected parameters，the initial structure was selected and the form of the Maxutov telescope was selected and improved. Then，the detection performance of the design results was analyzed. Due to the large range of high and low temperature changes in the outer space environment, the system lens barrel material analysis was carried out to obtain the influence of temperature changes on the energy distribution of the optical system. Finally，a tolerance analysis and optimization of the designed system were conducted so that it could meet the needs of processing and assembly. The design and analysis results indicate that the optical system adopts a spherical catadioptric mirror surface, the total length of the system is 171.2mm, the full field of view for a surrounding energy distribution is > 86%, the maximum magnification chromatic aberration value of monochromatic light is < 4 μm, the maximum absolute distortion is < 4 μm in 0.8 field of view. The system has a large field of view，aperture，and relative aperture. It is compact and of suitable size，easy to install，and offers high detection performance，high detection sensitivity，and a wide detection range. The optical system is useful for the accurate detection of high-precision target detection in a wide spectrum covering the near-infrared band of 0.8~1.9μm.