Abstract: A highly efficient optical device comprises two opposing active non-spherical optical surfaces defined by a two-dimensional representation that is symmetrically extended to provide a three-dimensional device. A focal area, spaced apart from the optical surface and non-contiguous therewith, is defined by the two opposing active optical surfaces. The active optical surfaces each have a continuous second derivative, and the optical surfaces are defined by a polynomial with an order of at least about twenty. The optical device may comprise a transparent dielectric core, and the optical surfaces may be formed on the core. A receiver may be situated at the focal area to provide a concentrator. An extended light source such as an LED may be situated at the focal area, to provide a collimator. Faceted embodiments can provide a low aspect optical device. In some embodiments a diffuser may be used to transform incident radiation into a predetermined shape.

Abstract: A highly efficient optical device comprises two opposing active non-spherical optical surfaces defined by a two-dimensional representation that is symmetrically extended to provide a three-dimensional device. A focal area, spaced apart from the optical surface and non-contiguous therewith, is defined by the two opposing active optical surfaces. The active optical surfaces each have a continuous second derivative, and the optical surfaces are defined by a polynomial with an order of at least about twenty. The optical device may comprise a transparent dielectric core, and the optical surfaces may be formed on the core. A receiver may be situated at the focal area to provide a concentrator. An extended light source such as an LED may be situated at the focal area, to provide a collimator. Faceted embodiments can provide a low aspect optical device. In some embodiments a diffuser may be used to transform incident radiation into a predetermined shape.

Abstract: The present invention is directed to disposable underpants including an underpant body having an inner surface and an outer surface, a longitudinal undercrotch portion, and front and rear end portions positioned at opposing ends of the longitudinal undercrotch portion and transverse thereto. A sanitary napkin member is positioned over the longitudinal undercrotch portion and extends substantially a length of the longitudinal undercrotch portion, the sanitary napkin including front, rear, and longitudinal edges. The sanitary napkin member is secured to the longitudinal undercrotch portion of the underpant body on the inner surface thereof and only along the rear and longitudinal edges of the sanitary napkin. An increased density of material is provided within the underpant body at the rear end portion thereof and coextensive with the longitudinal undercrotch portion, thus resisting tearing of the rear end portion during flexing of the disposable underpants.