Lens designs by ray tracing analyses for high-performance reflection optical modules

Abstract

Three kinds of novel optical modules are designed for high-efficiency light concentration.Each optical module consists of three components, namely a reflector, a secondoptical element (SOE) with a different parabolic profile and a concentrating lens. Aconcentrating lens with various profile designs is installed at the open end of the reflectorto improve the uniformity of ray irradiances collected at the solar cell chip. Aneffective process for finding the optimum design for the geometries of these opticalmodules is presented to obtain good uniformity in ray irradiance distributionand high optical performance. The results of ray tracing simulations indicatethat the optimum design is achieved based on the principle or the compromise ofhaving the lowest value of the highest peak of ray irradiances and the highestoptical performance. The optical module designed without a concentrating lenshas a relatively high peak at the center of the circular irradiance distribution.The use of a Fresnel lens can impede the high peak effectively and achieve verygood optical performance. Modules with spherical and aspherical concentratinglenses have irradiance peaks that are much higher than that of the Fresnel lensalthough their performance is negligibly higher than that of the Fresnel lens.