Improved coupling of light from a small arc lamp to a larger target

摘要

A light guide (8) is used to couple as much light as possible from an imaging source (1) having a large numerical aperture into a fiber optic component (7) with a relatively smaller numerical aperture. A tapered cladded rod, tapered fused bundle of optical fibers, tapered hollow reflective tube, CPC or negative lens when used as a light guide, provides for efficient coupling of light into a fiber optic component without loss of flux density. Such a system is especially advantageous when used with an imaging source that produces a very small image spot size with high numerical aperture, such as one producing a 1:1 image like a spherical off-axis reflector.