Research of aberration properties and passive athermalization of optical systems for infrared region

Abstract

Infrared optical systems are widely used for surveillance, military and many other purposes. Image quality of such systems should be stable over wide working temperature range from – 40 up to +60°C. Due to temperature dependence of properties of optical materials and mechanical parts it is a difficult task to achieve the required stability. Passive and active methods exist to compensate the most significant aberration – so called thermal defocus. Passive compensation ways are the most attractive because complicated mechanical parts or devices are not required. The work is aimed at developing and improving of the IR system design methods. The analysis of thermoaberrations starts with analysis of possibilities of chromatic and thermal defocus correction in two and three component systems. Based on these results the development and improvement of the design method which was proposed earlier was implemented. Examples of designed systems are given. Results of the work may be helpful for designers to find optimal material combination for further designing of thermostabilized systems working in IR region.