多层衍射光学元件斜入射衍射效率特性的研究

项目名称： 多层衍射光学元件斜入射衍射效率特性的研究

项目编号： No.60878030

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 崔庆丰

作者单位： 长春理工大学

项目金额： 36万元

中文摘要： 通过对多层衍射光学元件表面微结构、基底材料等参数的分析，获得了多层衍射光学元件衍射效率与入射角关系的理论结果。该结果表明，衍射效率随入射角的增加下降很快。对于一种具有典型意义的设计，当入射角为15 时，衍射效率为96%，20 时衍射效率为86%，入射角为33 时，衍射效率下降到零。为了从实验上验证该理论结果，设计并研制了一个多层衍射光学元件和一个含有该元件的折衍射混合光学系统的实验样机，搭建了衍射效率测量装置，完成了多层衍射光学元件衍射效率与入射角关系的实验测量。在排除了衍射元件较大加工误差的影响之后，实验测量得到的变化规律与理论研究结果揭示的规律一致，证明了理论研究结果的正确性。本工作揭示的多层衍射光学元件衍射效率与入射角关系的规律可用于指导多层衍射光学元件的设计和应用。 本项目研究中还提出了多层衍射光学元件优化设计的概念，并给出了优化设计的方法，由此，在同样的条件下可以获得比传统设计方法更高的带宽积分平均衍射效率；本项目也研究并给出了衍射效率与多层衍射光学元件加工误差的关系；本项目还研究了衍射光学元件应用于致冷红外成像时冷反射的分析方法，得到了有指导意义的理论结果。

中文关键词： 衍射光学；光学设计；成像系统

英文摘要： The theoretical relationship between diffraction efficiency of multilayer diffractive optics and incident angle was obtained. The theoretical result shows that the diffraction efficiency decreases rapidly with the increase of incident angles . The diffraction efficiency is 96% for 15 degree incident angle, 86% when the incident angle increases to 20 degrees, and the diffraction efficiency drops to zero when the incident angle increases to about 33 degrees for a typical design. In order to verify the theoretical result,a hybrid diffractive-refractive lens with a double layer DOEs was designed and prototyped, and a testing bench was set up for experimental measurement. The tested diffraction efficiency variation with the incident angle shows that it was in accordance with the prediction of the theoretical result, though the diffraction efficiency for normal incidence is apparently lower than 100% because of the fabrication error of the double layer diffractive optical element. The discovered law of the diffraction efficiency variation with the incident angles can be used as a rule for hybrid lens design and application with multilayer diffractive optics. the concept of optimization design of multilayer diffractive optics was proposed,and the optimization method was given,by which higher wave-band integral diffraction efficiency can be obtained. The effect of fabrication error of multilayer diffractive optics on diffraction efficiency was analyzed and significant result obtained. We also gave a method for nacissus analysis of diffractive optics for infrared imaging.

英文关键词： diffractive optics; optical design; imaging systems