In this work we analyze a two-stage concentrator in which the first stage is reflective and the second stage considers the first one as a Lambertian source in order to obtain the highest possible gain. We determine the profile and the position of this first stage, which happens to be a parabola, and we calculate the value of the gain as a function of the acceptance angle and the focal length of the first stage.
© 1980 Optical Society of America
Antonio Luque, "Quasi-optimum pseudo-Lambertian reflecting concentrators: an analysis," Appl. Opt. 19, 2398-2402 (1980)