红外3.2～4.5μm波段折射/衍射光学系统的减热差设计

研究了折射/衍射光学元件的温度效应及红外系统的设计理论及具体实例,给出了在红外3.2～4.5μm波段,5°视场范围,冷光栏效率100%,在-40～80℃温度变化范围情况下的红外混合减热差系统的设计结果.结果表明,使用折射/衍射光学系统的减热差设计方案,可令相应的传统光学系统减少一片元件,并且节省了昂贵的硒化锌红外材料.不仅能在较大视场内得到接近衍射极限的成像质量,较宽的温度工作范围,而且结构简单,体积小,重量轻.

Design on the athermal infrared diffractive/refractive optical system in 3.2～4.5μm

Based on the investigation on the thermal properties of the diffractive lens, the paper introduces a method and some examples for designing the athermal diffractive/refractive optical system in the infrared region. An optical system at 3.2～4.5μm with 100% cold shield efficiency, 5-degree field of view was designed, associated with high optical quality at the temperature ranging from -40℃ to 80℃. With this designing scheme, there is decrease in the number of optical components for a conventional optical system by one piece, and the weight can be reduced by 1/4, and expensive Se-Zn IR material is saved. Furthermore, the image quality approaching the diffraction limit in a larger spatial field view and wider thermal range can be obtained.