紧凑型折/衍混合中波红外无热化成像光学系统

Compact Refractive and Diffractive Hybrid MWIR Athermalizing Optical Imaging System

分析了衍射光学元件的温度特性,利用衍射光学元件,设计了工作波段在中波红外、全视场为5.2°的红外无热化成像光学系统。设计结果表明,该光学系统在-55℃^+80℃的温度范围内系统的MTF接近衍射极限,全视场内的MTF数值在33 lp/mm处达到0.5,像质优良。该光学系统最大直径为110 mm,总长90 mm,满足了技术指标要求。

The temperature characteristics of diffractive optical element are analyzed. An infrared athermal im-aging optical system at MWIR bands and 5.2° field of view is designed by using diffractive optical element. Designresults show that the image quality of the system approaches the diffraction limit in the working temperature rangeof-55 ℃ to ＋ 80 ℃, and the entire field of modulated transfer function（MTF） at 33 lp/mm is more than 0.5. Themaximum diameter and the total length of the optical system are 110 mm and 90 mm respectively, which meets thetechnical requirements.