Optical design of long transmission type ultraviolet detection system

Abstract

Ultraviolet (UV) detection and imaging technology has developed rapidly in military applications due to its simple environment and clean background. Especially in the ultraviolet communication, UV alarm, UV detection and UV guidance has a unique advantage. A medium telephoto transmission type UV optical system was designed using optical software. This system consisting of two aspheric surfaces and one binary diffractive surface and the other 10 spherical surfaces is adopted to realize the long-wavelength infrared image design parameters: UV operating waveband of 240- 300nm, focal length of 200mm, field of view (FOV) of 24.8 degree, the F number of 2, and total length of 210mm. By optimizing materials and distributing power properly the system characteristics have been greatly improved. After optimization, the MTF is higher than 0.7 at the 20lp/mm and the maximum RMS radius is only about 10 μm, which is much smaller than pixel size of the detector whose pixel size is 13.5μm×13.5μm. The energy concentration in UV CCD receiving surface is greater than 82%. Under the premise that the system meets the UV warning and detection optical properties, the use of aspheric surfaces reduces aberrations, simplifies the structure. This system has high imaging quality and simple structure. In terms of warning, it has good concealment, small size and light weight advantages.