Light conductor with coupling surface - has beam coupling wedge shaped extension of surface where cladding is removed

摘要

A light conductor (10) is provided with a coupling surface. Over a short area (20) of the conductor the coating (12) around the core (11) is removed. The coating in this region (20) is replaced by a material (13) which has a higher refractive index than the core (11). Pref., the higher index material (13) is placed on the conductor such that it has a triangular cross-section (14). The triangle is pref. a right-angled triangle whose hypoteneuse is parallel to the core (11) and slopes upwards in the beam advancing direction. The gradient of the short side (15) of the triangle (14) so that the emergent light (17) is not guided back into the core. The output surface (18) of the extension (14) may have a convex curved surface. ADVANTAGE - Increases degree of out-coupling of conductor and greatly reduces energy loss.