谐衍射/折射双波段系统设计

The Dual Band Design of Harmonic Diffractive-Refractive Optics System

将谐衍射透镜成功地引入红外凝视阵列探测器双波段系统的设计中 ,使系统在 3.7～ 4 .3μm的中波红外和8.7～ 11.5 μm的长波红外波段同时较好的完成了像差校正。光学传递函数在两个波段范围内 ,在 18lp/mm时的归一化值均大于 0 .5 ,接近衍射极限。该系统具有 10 0 %冷光栏效率。设计结果表明 ,谐衍射透镜的光谱特性介于折射透镜与衍射透镜之间 ,色散大小可以控制 ,降低了对工艺水平的要求 ,使红外双波段系统结构紧凑 ,透镜组片数少、分辨率高。为红外光学设计提供了一种全新的器件。

Harmonic diffractive element (HDE) is successfully introduced to the system of infrared dual band staring-array detector. It simultaneously accomplished the rectification of the aberration both in the mid-infrared band of 3.7～4.3 μm and far infrared band of 8.7～11.5 μm. In the dual band optical transfer function (OTF) approaches the diffraction limit, which the normalized ratios are all larger than 0.5 in 18 cycle/mm. The system has 100% cool diaphragm efficiency. The design results show that the spectrum characteristic of HDE is compromise between refractive element and diffractive element. The dispersion of HDE can be controlled according to the demand of system, and the fabrication demand for technical level is decreased, and it make the system structure compact, has less elements and high transmittance. The HDE offers a new component for infrared optics designs.