红外光学系统中衍射面冷反射的分析与评价

研究了含有衍射面的红外光学系统中冷反射产生的原理, 并指出了衍射表面与折射表面的冷反射的差别. 光线在经过衍射表面后会发生多级衍射, 本文在考虑衍射效率的基础上定量分析了衍射表面的冷反射, 采用对衍射光线进行近轴光线追迹的方法, 给出了针对衍射表面冷反射的新评价标准. 结合一个折衍射混合中波红外光学系统实例, 具体分析了光学系统中衍射表面对冷反射的影响. 研究结果为红外光学系统中衍射表面的冷反射的分析与评价提供了一种全新的方法.

Evaluation and control of narcissus for diffractive surfaces in IR systems

The narcissus influence for cooled IR imaging systems is well known and should be considered in the process of optical design.We gave a comprehensive introduction and analysis of the cause of narcissus for IR optical system and pointed the difference between diffractive surface and refractive surface for narcissus intensity evaluation.There will be multi-order diffraction after rays passing through diffractive surface.Considering the diffraction efficiency,we analyzed the narcissus influence for diffractive surface and modified the narcissus evaluation criterion YNI.A MWIR optical system with two diffractive surfaces has been given as a practical example and the narcissus effect for the two diffractive surfaces has been evaluated.The conclusion can be used to calculate and control the narcissus intensity in infrared optical systems with diffractive surfaces.