Projection Optical System Design of Dynamic Dual-band Infrared Scene Simulator based on DMD

According to the application requirements of the dynamic infrared scene simulator, a projection optical system of coaxial dual-band infrared(middle wavelength 3～5μm and long wavelength 8～12μm)scene simulator is designed in this paper. The structure is simple,composed of only four pieces of spherical lens and one projection prism.Ge、ZnS and ZnSe are used to achieve the dual-band infrared achromatism. At the cut-off frequency 17 lp/mm and the image distance 5.1mm,the MTF of middle wavelength is greater than 0.7;the MTF of long wavelength is greater than 0.4. The result shows that the MTF of the system is close to the diffraction limited curve and the image quality is perfect. The system meets the requirements of the overall design of the infrared scene simulator.