A structure is formed which is prepared as a via for electrical contact passing through layers of an optical waveguide, in a multilayer structure including an electrical substrate and the laminated layers of the optical waveguide. The surface of an electrode pad is plated with solder. The layers of the optical waveguide are formed above the portion plated with solder are removed to expose the portion plated with solder. A device is prepared having both a light-emitter or photoreceptor in optical contact with the optical waveguide, and a stud (pillar). The stud (pillar) is inserted into the portion in which layers of the optical waveguide have been removed, and the plated solder is melted to bond the electrode pad on top of the electrical substrate to the tip of the inserted stud (pillar).