An optical hybrid module and method of manufacture includes a plurality of optical devices integrated on an optical waveguide substrate. The structure helps to reduce optical crosstalk among the plurality of optical devices caused by reflections of leakage lights within the optical hybrid module. The optical hybrid module includes a substrate, an optical waveguide formed on the substrate for performing transmission of optical signals, a plurality of optical devices mounted on the substrate to be optically coupled with the optical waveguide, and a light blocking layer formed to have an inclined profile at opposite sides of an end surface of an optical coupling portion centrally provided in the optical waveguide. The light blocking layer serves to prevent light from entering the optical devices, through regions other than the optical waveguide.