Benson Michael R, Marciniak Michael A
Opt Express. 2013 Nov 18;21(23):27519-36. doi: 10.1364/OE.21.027519.
Hemi-ellipsoidal mirrors are used in reflection-based measurements due to their ability to collect light scattered from one focal point at the other. In this paper, a radiometric model of this energy transfer is derived for arbitrary mirror and detector geometries. This model is used to examine the imaging characteristics of the mirror away from focus for both diffuse and specular light. The radiometric model is applied to several detector geometries for measuring the Directional Hemispherical Reflectance for both diffuse and specular samples. The angular absorption characteristics of the detector are then applied to the measurement to address measurement accuracy for diffuse and specular samples. Examining different detector configurations shows the effectiveness of flat detectors at angles ranging from normal to 50°, and that multifaceted detectors can function from normal incidence to grazing angles.
半椭球形镜因其能够收集从一个焦点散射到另一个焦点的光而用于基于反射的测量。在本文中，针对任意镜和探测器几何形状推导了这种能量转移的辐射测量模型。该模型用于研究镜在离焦情况下对漫射光和镜面光的成像特性。辐射测量模型应用于几种探测器几何形状，以测量漫射和镜面样品的定向半球反射率。然后将探测器的角吸收特性应用于测量，以解决漫射和镜面样品的测量精度问题。研究不同的探测器配置表明，平面探测器在从法线到50°的角度范围内有效，而多面探测器可以在法线入射到掠射角范围内发挥作用。
