METHOD FOR BRANCHING AND JOINING OPTICAL FIBER CIRCUIT AND BRANCHING AND JOINING CONNECTOR

摘要

PURPOSE:To enable efficient and stable taking out of leak light by guiding the leak light component generated at the connection point of optical fibers to the outside of the optical fibers and taking out the same through an optical window provided to a part of a connector plug to a 3rd optical fiber on the outside. CONSTITUTION:Part of the signal light propagating in the optical fiber 10a is made into the leak light by the fiber spacing formed by a film 9. This leak light is trapped in a photoconductive sleeve 5b having the refractive index equal to or larger than the refractive index of a fiber clad and is propagated at a low loss in the sleeve to a terminal part. The terminal face of the photoconductive sleeve forms a reflecting surface 6 set at 45 deg. with the optical axis and a transparent window 7 is provided on the side face of an adapter 41b facing said reflecting surface and, therefore, the leak light component can be taken out to the outside of the plug. The reflecting surface 6 is constituted as a concave reflecting mirror and the light is condensed to an optical fiber 30 for branching by using a rod lens 31 for condensing, by which the signal light is efficiently branched.