JPS5629204A - Optical branching circuit - Google Patents

Abstract

PURPOSE:To achieve highly reliable optical branching circuit having excellent branching property, by forming light guide paths upon the substrate made of either plastics or glass, etc., by the photographic means, using photosensitive resin having higher refractive index than said substrate, and also by forming optical branching circuit by covering the light guide paths with transparent material having lower refractive index than said paths. CONSTITUTION:Smooth substrate 1 made of either transparent resin, glass or quartz glass, is coated with photosensitive resin such as polyester base or polyurethane base, and covered with ''MYLER (R)'', and the glass mask is tightly set over said surface, and the resin is then hardened by irradiation of ultraviolet rays. Light guide paths 2 are then formed by alkal etching. Optical fibers 4-51 are then coupled together by having respective axes aligned along the side surfaces of said light guide paths 2 which are then covered entirely with transparent material 3 such as setting resin having lower refractive index than the photosensitive resin. After hardening, the optical branching circuit is thus accomplished. Accordingly, highly reliable optical branching circuit having excellent branching propertu is realized.