It is necessary to analyze the spectral distribution of sunlight on focal spot, because the spectrum at the focusing spot is different with the solar spectrum, as is proved by experiment. The spectral spatial distribution on the focal plane is consistent; therefore it can be used for calculating absorption efficiency of any shape laser medium pumped by Fresnel lens. Based on the absorption spectrum of Cr/Nd:YAG ceramic, this paper studies the convex Fresnel lens focus solar light. Meanwhile, Fresnel lens for the purpose of image projection is contrasted with highly concentrating Fresnel lens. By way of simulation, the maximum absorbing power density of 6 designs, based on the purpose of obtaining the maximum power density, is 279.2 W/cm<sup>2</sup>, which is 3%–16% higher than absorbing power density based on the purpose of image projection.
© 2013 Optical Society of AmericaPDF Article