Long focal length large aperture middle infrared continuous zoom optical system

For cooled detector with staring focal plane array, a long focal length large aperture middle infrared continuous zoom optical system was presented. The zoom system is composed of eight lenses and two reflectors. The parameters and schematics of the system are given by using zoom system principle and optical design software. The image quality and narcissus of the system are analyzed. The system with 3.7~4.8μm spectial region can realize 88~1100mm range continuous zoom and fulfill 100% cold shield efficiency. The system has the advantages of long focal length, large aperture, high image quality and smooth zoom locus.