Thermal design for infrared refractive/diffractive hybrid infrared optical system

The principle and design method of employing diffractive optical elements to athermalize and achromatize an optical system are expounded.The optical prescription and evaluation of an athermalize and the focus length is 70.3 mm,F/# is 2 infrared optical system in temperature range-40~60 ℃ and 3~ 5 μm waveband are given.Additionally,in order to compare,a pure refractive system is also designed,two systems have the same optical performance parameters.Hybrid system has effectively reduced the chromatic aberration,and significantly improved the image quality,besides,a compact structure、light weight and athermalize are other advantages of hybrid system,which making diffractive optical lenses get more extensive applications in the optical field.