Optical System Design And Stray Light Analyze Of Dynamic Scene Simulator With Wide Spectral Region And Large Relative Aperture

With the wide application of imaging homing technology in the field of aerospace,visible and infrared imaging and detection technology have been developed.The development of visible and infrared imaging and detection system needs to test and evaluate the system in order to ensure the system performance meet the requirements.Target simulator is used to provide simulation scenarios and targets for the system under test when testing system performance.In this paper,we designed a visible and infrared dynamic target simulator with wide spectrum and large relative aperture,the optical system design and stray light analysis technology in the target simulator were studied.Achieved an accurate simulation of the broad spectrum and large relative aperture visible and infrared dynamic target.In this paper,the overall structure of the target simulator was designed according to the working principle of the broad spectrum dynamic target simulator.Through the comparison of multiple image generation devices,the DMD device with the advantages of wide working spectrum and good uniformity was used as the image generating device.By designing the visible and infrared lighting systems separately,and using the condenser's critical lighting as the lighting method,achieved the broad spectrum lighting of DMD.A collimated projection system with wide spectrum and large relative aperture was used as the target projection system,achieved a broad spectrum target simulation.Then,the optical system of the target simulator was designed.Analyzed the indicators of the collimated projection optical system in the target simulator,the band of the system was 0.4 ~ 5?m,the field of view was 1.8 ° × 1.4 °,the F number was 2.56,the focal length was 460 mm,was a broad spectrum and large relative aperture optical system.Used a high-order aspheric off-axis three mirror structure to design the system,the image quality of the designed system was close to the diffraction limit,met the engineering requirements of the system.Designed the visible and infrared condenser with the optical design and simulation software Zemax and Tracepro,a wide range optical systems with uniform illumination were designed,achieved a broad spectrum of uniform lighting.Finally,used the software Solidworks and Tracepro to establish the complexspatial model of the target simulator.Analyzed the stray light coefficient of the collimation projection system in the target simulator,the correctness of the model was verified by comparing the results of the analysis with the measured results.Analyzed the stray light of the target simulator,through the analysis,the ghosting problem in the target simulator was found and realized the accurate positioning.The ghosting problem was solved by the method of optimizing and improving the structure of the beam splitter in the simulator.After the design of the optimized system,the stray light had been effectively suppressed,and the light energy of each kind of stray light was less than one order of the imaging beam.Evaluated the stray light level of the system indirectly by imaging contrast,the imaging contrast of the system needed to be better than 1:10,and through the calculation,the contrast of the visible image was 2.45%,the contrast of the infrared image was 9.42%,which satisfied the imaging contrast requirement of the system.