Optical design of MWIR detection system for near-space infrared detecting

Abstract

Near-space platform has a high signal contrast and a long detection time. In order to realize effective detection of low altitude penetration target, a middle wave infrared (MWIR) optical system used in near space detection with high optical performance is given. First, the optical system scheme was described. Then on the basis of instrument and system consideration, the optical design parameters were distributed reasonably. The system had an effective focal length of 600 mm, an F-Number of F/4, a field of view of 2ω=1.16°, spatial resolution of 18 lp/mm and a working wavelength range of 3～5μm. The system structure is simple. And the requirements of the spot, energy concentration, distortion are all satisfied. Because the change of environment temperature will deeply influence image quality of MWIR optical system, the temperature characteristic of the system is analyzed. Moreover, first -order ghost and narcissus effect of the system are all analyzed in CODEV software. The analysis results show that temperature, first-order ghost and narcissus effect requests are all satisfied.