Asymmetric second-stage concentrators.

Given a linear (2-D) primary optical concentrator and a convex close surface of any shape and location (within known limits) underneath, an ideal second-stage reflective element that redirects the primary radiation onto a section of that surface may be designed. A useful application is to asymmetric two-stage concentrators for solar energy, the primary of which is not shaded from the illuminating source by the secondary.