Design of infrared diffractive/refractive search and trace optical system beyond normal temperature

To meet enviroment performance of infrared search and trace optical system,a novel optical system beyond normal temperature of infrared camera in 3.7-4.8 μm with 11.42 degrees of field of view was designed.The IRST system was consisted of three lenses,including two aspheric surfaces and a diffraction surface,which had only two materials Ge and Si.The optical system had compact structure,small volume and light weight.The image quality of the system approached the diffraction limit in the temperature range-80-160℃.It was compatible with staring focal plane array which had a format of 320×۲۴۰ and the pixel pitch of 30 μm,the infrared search and trace system have jarless and good performance beyond normal temperature.The recognition distance of the system was calculated.The system can recognize a vehicle target from 1.0 km.