JPS6415708A - Production of optical fiber coupler - Google Patents

Abstract

PURPOSE:To improve the environmental resistance of a joint part by fixing an optical fiber into the groove of a substrate in such a manner that the part upper than the core of the fiber projects from the groove, polishing the projecting part to expose the part near the core and joining the polished surfaces to each other, thereby forming a coupler. CONSTITUTION:The optical fiber 14 is fixed by an adhesive agent 15 into the groove which is so formed to the substrate 12 as to be shallow in the central part of the substrate and to be deeply curved on both sides. The depth in the shallowest part of the groove is so set that the clad 12 existing in the part upper than the core 3 of the optical fiber 14 projects. This substrate is then coated and solidified with a synthetic resin, etc., soluble in a solvent and after the clad 2 is polished near to the core 3 of the fiber 4, the covering is removed by a solvent to form the polished surface 18. Since the surface 18 projects slightly from the substrate 19, a spacing is not generated between the substrates even if the coupler is formed by joining the two substrates at the polished surfaces. The coupler which is less changed in the coupling characteristic by a temp. change, etc., and has the excellent environmental resistance is obtd.