OPTICAL WAVEGUIDE, AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide an optical waveguide which achieves the reduction in propagation loss of light by eliminating the occurrence of a cavity in an upper clad layer, and to provide a manufacturing method thereof.SOLUTION: A method of manufacturing an optical waveguide includes: an upper clad layer formation step of depositing a cladding material on a surface of an under clad layer having an optical waveguide core formed therein, by a CVD method to form an upper clad layer; an etching step of etching the upper clad layer in an etching depth for leaving the upper clad layer by anisotropic dry etching to form the remaining layer of the upper clad layer, in which a side wall standing from the under clad layer so as to cover the optical waveguide core and having a curved surface curved like an arc toward an upper surface of the optical waveguide core is formed on a side surface of the optical waveguide core; and an upper clad layer additional formation step of depositing the cladding material on the remaining layer by the CVD method to form the upper clad layer increased in thickness.