JPS57173804A - Substrate for optical circuit - Google Patents

Abstract

PURPOSE:To form an excellent optical waveguide by which an optical device such as an optical IC, etc. can be integrated and made small-sized easily, by forming a buffer layer whose refractive index is smaller than an optical propagation medium layer and forming the optical propagation medium layer on said buffer layer, in a substrate whose surface has been covered with the optical propagation medium layer. CONSTITUTION:In a substrate for an optical circuit, on a substrate 32 such as a GaAs single crystal substrate or a substrate of MgO, SrTiO3, spinel, etc., a buffer layer 33 is formed by quartz glass, silica glass, borosilicate glass, etc., on which an optical propagation medium layer 31 is formed by one or more kinds of ZnO, ZnS, ZnSe, CdS, CdSe, CdO, CdTe, BaTiO3, PbTiO3 and PLZT compounts, a refractive index of the buffer layer 33 is made smaller than that of the medium layer 31, and also the layer 33 is constituted so as to be in a matching state with a crystal lattice of the contact surface with the substrate 32. In this way, an optical propagation loss of the optical waveguide 31 is reduced and the integration is executed easily so that an optical device can be made small-sized, and an optical IC can be integrated.