THREE-DIMENSIONAL OPTICAL WAVEGUIDE DEVICE HAVING BRANCHING AND COUPLING PART

摘要

PURPOSE:To increase the branching angle in a branching and coupling pat and to minimize the loss of light by forming a recess around an optical waveguide part for branching and coupling and forming only the optical waveguide for branching and coupling into a ridge type. CONSTITUTION:The entire part of the three-dimensional optical waveguide can be prepd. by a technique consisting mainly of photolithography. The three- dimensional optical waveguide of an embedment type is formed by diffusing thermally and selectively Ti onto the surface by a substrate 1. Only the periphery of the Y-shaped optical waveguide part 10 for branching and coupling of such optical waveguide is formed to a recess 20 by etching, by which the part 10 is made into the ridge type optical waveguide. Only the part 10 is worked to the ridge type and therefore the working range using an electron beam depicting device is extremely narrow. The operation thereof can be executed in a short period. Since the electron beam depicting method can be adopted, the working with high accuracy is possible and the top end of the branching part is sharp-angled. The loss of light is minimized without the generation of mode conversion.