An optical communication device includes a support substrate, an optical waveguide, and a detector. The optical waveguide includes a first cladding layer that is formed on the support substrate, and is composed of silicon oxide or a material containing silicon oxide; a second cladding layer formed on the first cladding layer; and a core that is formed within the second cladding layer or between the first cladding layer and the second cladding layer, and is composed of silicon or a silicon-containing material. The detector contacts a part of the core, and is adapted to detect an intensity of light propagating through the core.