Infrared optical system athermal lens design

In recent years, with the rapid development of science and technology, in particular the increasingly sophisticated infrared detector technology and processing technology, infrared systems are increasingly used in various fields, especially in the military field. Infrared homing guidance precision-guided project has become one of the world's countries in military applications focus of research and development, at the same time, with the use of environment has become increasingly complex, the infrared system performance requirements are also increasing. Infrared optical system is the entire infrared system in a very important part, it can directly affect the performance of the whole system, and thermal effects is an important factor affecting infrared optical system performance, so for non-thermal effects of infrared optical system design methods study it is very necessary.

An optical system is usually designed only consider normal temperature conditions, such an optical system designed to use under normal conditions is possible, however, if used under very warm conditions, the optical performance will be poor. The main reason for this phenomenon is as the ambient temperature changes, the optical system of the optical element and the supporting member of the optical element of the mechanical physical properties change, i.e., the temperature coefficient of the refractive index and the linear expansion coefficient exists, resulting in the optical performance of the system decline.

 

Athermal design is the use of different means to eliminate the effect of ambient temperature change on the performance of optical systems. 1930s, Park Lane (J .W. Perry) and other researchers on the impact of temperature changes in the optical system, and presents no heat setting (thermalisation) concept, after Jiami Sen (Jamieson), Rutgers continue to study (Rogers) and the Kana Jia Wa (Kanagawa) and others, especially for non-thermal infrared system suggested several design techniques: no thermal mechanical, optical passive and electromechanical technologies without heat-free heat technology. The past 20 years, people made off diffraction Athermalized technology, which is the use of diffraction effects folded optical system to achieve athermal, the wave theory of light, it will be applied to non-thermal design of the optical system.