Research On The Optical System Of Infrared Scene Simulator Based On DMD

In the laboratory,the infrared scene simulator can project dynamic infrared images to test the performance of the infrared seeker,which has the advantages of high efficiency,convenience,economy,and good repeatability.This paper analyzes and compares the imaging principles,advantages and disadvantages of several infrared scene generation devices.In order to project infrared dynamic images with high resolution,high frame rate and high gray level,a research on infrared scene simulators based on digital micromirror devices is carried out.The main work content of this article is to write the program of infrared scene simulator optical system design and simulation.With the help of the program,the design of the optical system of the long-wave infrared scene simulator based on DMD is completed and the simulation imaging effect is analyzed.The main research contents are as follows:(1)Introduce the structure and working principle of DMD chip,DMD optical window replacement and gray modulation method.A program for designing and simulating the optical system of the infrared scene simulator is written.This program can design the optical system and simulate the imaging process of the optical system to obtain the simulated image and analyze the influencing factors of the quality of the simulated image.Taking the design of the long-wave infrared scene simulator as an example to carry out research.(2)The illumination optical system of the long-wave infrared scene simulator composed of the illumination light source and the illumination relay lens is designed.Design two kinds of illumination light source composed of area source blackbody and uniform light rod.Using the optical software TRACEPRO for optical simulation to obtain the illumination uniformity of the two illumination sources.The effects of the length of the uniformity bar and the temperature uniformity of the surface blackbody surface on the uniformity of illumination are simulated and analyzed,and analyzed and verified through experiments.Using critical lighting to illuminate the DMD chip,two lens-type lighting relay lenses were designed using the optical software ZEMAX.(3)A total reflection beam splitting prism is introduced to solve the problem of collision between the illumination optical system and the projection optical system.Analyze the advantages and disadvantages of the three different beam splitting methods,and finally choose the total reflection prism as the beam splitting lens.According to the working band of the infrared scene simulator,zinc selenide is selected as the material of the total reflection prism,and the size of the total reflection prism is designed and calculated.(4)According to the performance indexes of the infrared seeker and DMD,the parameters of the projection optical system of the long-wave infrared scene simulator are determined.The optical software ZEMAX is used to design a projection optical system composed of two lenses,and the image quality of the projection optical system is evaluated.(5)The simulation image is obtained through the optical system design and simulation program simulation.Compare the simulation image and the original simulation image to verify the rationality of the optical system design.Analyze the influence of the uniformity of the illumination light source and the tolerance of the projection optical system on the quality of the simulated image.