Shaped nonimaging Fresnel lenses

Shaped nonimaging Fresnel lenses have been designed according to the edge-ray principle, incorporating any combination of two acceptance half-angle pairs. A numerical solution yields nonimaging lenses consisting of minimum-deviation prisms. If the outer surface of the lens must be smooth, the lens shape will be convex. A linear lens prototype intended as concentrator for the collection of solar energy has been designed, manufactured and tested. Results in terms of flux distribution and the optical concentration ratio are presented. Shaped nonimaging Fresnel lenses are suited for application as solar concentrators, or as collimators, or in Lighting applications, where they can fulfil technological requirements as well as being adaptable to the necessities of fashionable design.