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.
