Design of Visual Light and Middle Infrared Zoom Optical System

In order to achieve wide range for target search and monitor in all-weather, a zoom optical system with long focus length is designed which is used for visual light and middle infrared observation in this paper. In this system, the visible and infrared optical paths share a fixed R-C mirror in the foreside, on whose image surface the parallel plates is used to separate the light beam. Then the dual wavelength band zoom is achieved by two optical transmitted systems whose aperture is 100mm, Zoom range is 300mm~900mm for visual light and 250mm~750mm for middle infrared.This system has stable image and good imaging quality, satisfies the requirements of the application.