Patent ID: 7789531

Claim:
An LED comprising: a quantum well region operable to generate light; and a shaped substrate having an interface to receive light generated by the quantum well region, wherein light generated by the quantum well region traverses the interface, the shaped substrate comprising: an exit face opposite from and a distance from the interface, wherein the substrate is shaped so that a portion of the light entering the shaped substrate through the interface will exit the shaped substrate through the exit face and wherein the exit face has at least 70% of a minimum area necessary to conserve radiance for a desired half-angle of light projected from the shaped substrate; and a set of sidewalls, wherein each sidewall is positioned and shaped so that at least a majority of rays having a straight transmission path from the interface to that sidewall can reflect through total internal reflection to the exit face with an angle of incidence at the exit face at less than or equal to a critical angle at the exit face.