Abstract: A cylindrical light source comprises multiple LEDs mounted on either the exterior or interior surface of the cylinder, with heat-sink fins respectively on its interior or exterior. The LEDs emit radially, but their emission is redirected along the cylinder axis by individual ellipsoidal reflectors.

Abstract: A waveguide version of a Kohler integrator is disclosed, utilizing geodesic lenses with a surface that can be mapped to a gradient-index Luneburg lens or to a nonfull-aperture Luneburg lens in such a way that the light paths in the gradient index lenses map into the geodesics of the surface, with the outer region of the gradient index lenses mapped into a flat surface. Arrays of these can be applied to lines of LEDs, as in CHMSLs, to mix light in intensity and in illumination as well as to avoid the deleterious effects of binning and burnout, or in multicolor arrays, to ensure complete chromatic mixing.