Optical System Design Of An Infrared Zoom Lens

Infrared systems are used for a wide variety of national security, military and industrial purposes. The design method of infrared zoom lenses was researched in this thesis. The characteristic of infrared system, the design method of zoom lenses, the application of diffractive elements in the optical system and the design of cam curves are also discussed.A refractive infrared continuous zoom optical system in the long wave8-12μm region is designed. The system is a3×f/1zoom lens, the effective focal length range from50mm to150mm. The image height is11mm and the total length of the system is less than210mm. The system has five elements with germanium only. The length of system is decreased and the image quality is improved by mechanical compensation, binary surface and aspheric surfaces. Finally, optimized cam curves are designed.