From Event: SPIE Optical Engineering + Applications, 2018
The bidirectional reflectance distribution function (BRDF) plays a fundamental role in the optical characterization of a surface. The BRDF is a measure of the amount of light incident from one direction which is scattered by a surface in another direction. Integrating the BRDF over specified incidence and reflected solid angles defines the bihemispherical reflectance, which can be related to the absorptance and emissivity of a surface. We have designed and fabricated a high-accuracy bidirectional reflectometer and used it to measure the bidirectional reflectance of a smooth silicon substrate coated with the black absorber Aeroglaze Z302®. Two different coating thicknesses displaying different degrees of surface roughness were studied. A BRDF model consisting of diffuse, glossy, and specular components was then fitted to the experimental results. Finally, the Monte Carlo ray-trace (MCRT) method was used to split an incident beam into a group of reflected rays whose power and direction were determined by the BRDF model. The combined model is capable of simulating the performance of any optical instrument which has Z302 coated on its active surfaces. As a demonstration, the combined model is used to simulate the performance of the bidirectional reflectometer experiment used to obtain the original data.
Deepali Shirsekar, Yifei Wang, J. Robert Mahan, Kory J. Priestley, and Vinh Q. Nguyen, "Bidirectional reflectance measurement of black absorber layers for use in optical instrument design," Proc. SPIE 10743, Optical Modeling and Performance Predictions X, 1074303 (Presented at SPIE Optical Engineering + Applications: August 22, 2018; Published: 17 September 2018); https://doi.org/10.1117/12.2320347.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the proceedings. They include the speaker's narration with video of the slides and animations. Most include full-text papers. Interactive, searchable transcripts and closed captioning are now available for most presentations.
Search our growing collection of more than 25,000 conference presentations, including many plenaries and keynotes.