Image Number 19 for United States Patent #6898353.
An optical coupling element for use in large numerical aperture collecting and condensing systems. The optical coupling element includes a curved surface such as a lens at the output of a tapered light pipe (TLP). The TLP in combination with the curved surface alters the divergence angle and the area of the light exiting the curved surface. Electromagnetic radiation emitted by a source is collected and focused onto a target by positioning the source of electromagnetic radiation substantially at a first focal point of a primary reflector so that the primary reflector produces rays of radiation reflected from the primary reflector that converge at a second focal point of the secondary reflector. The optical coupling element is positioned so that its input end is substantially proximate with the second focal point of the secondary reflector. The converging rays of radiation reflected from the secondary reflector pass through input end and are transmitted towards the curved surface, where their divergence angle and area are adjusted.