Long Wavelength Infrared Continuous Zoom Optical System

For cool 320×240 detector with staring focal plane array, a long wavelenght infrared continuous zoom optical system was presented. The zoom system is composed of seven lenses and two reflectors. The parameters and schematic of the system ware given by using zoom system principle and optical design software. The image quality and narcissus effect of the system ware analyzed. The system with 8~12μm spectral range can realize 40~240 mm range continuous zoom and fulfil 100% cold shield efficiency.The system has the advantages of simple structure, high image quality, easy adjustion, short zoom journey and smooth zoom locus. Keywords- infrared optical system; continuous zoom; optical design