Optical design of transmission/reflection common aperture infrared/laser composite seeker

In order to realize the miniaturization and low cost of infrared/laser dual-mode seeker imaging system and simplify the optical system structure, a transmission/reflection common aperture infrared/laser composite seeker optical system is designed. Firstly, the structure, overall scheme and working principle of the system are studied. The optical system uses the common aperture design at the front, and the infrared and laser signals are separated by the spectroscope at the backend to enter the respective detectors. The whole optical system shares the same receiving aperture, the structure is compact, and meets the requirements of miniaturization of the seeker. The system can not only meet the requirements of large field of view in the target searching stage, but also meet the requirements of accurate recognition and tracking of the target. Based on the design metrics and parameters, the infrared optical system and laser optical system are designed and analyzed respectively. Through the analysis of action distance, the aperture and focal length of infrared and semi-active laser subsystems are designed. Simulation results show that the transfer function MTF and optical transmittance of the infrared optical system meet the design requirements, and the spot energy, linear region and optical transmittance of the semi-active laser subsystem meet the requirements.