The invention provides an
infrared target simulator focusing collimation projection optical
system and a design method thereof. The optical
system is composed of a
telescope objective, an intermediate field lens and a
relay lens group. A source target and a
background image generated by the
infrared target simulator are input into the DMD and then are incident to the focusing collimation projection optical
system through the DMD, the incident light firstly passes through the
relay lens group and the intermediate field lens to generate a primary image of the image on the DMD, and then the primary image surface is collimated and projected to an
entrance pupil of a tested photoelectric device through the
telescope objective. According to the invention, optical material parameters are finely analyzed and matched, three
infrared optical materials are adopted to form a lens group, a field lens is added to compress the aperture of a
light beam, and only five lenses are used, so that achromatism and
athermalization are realized while
high transmittance is ensured. And a focusing lens group and a precise mechanical structure are arranged in the
relay lens group, so that the target
simulation requirement of photoelectric detection equipment such as a guide head at a wider
working temperature range is met, and meanwhile, the requirement of obtaining a clear
simulation target scene by matching detected photoelectric equipment with different working distances can be met.