Optical waveguide, optical module, and their fabrication method

摘要

It is a problem of disclosed technology to provide a polymer optical waveguide substrate having a V-groove for fiber alignment providing optical coupling with an optical fiber with low loss. According to a resolution means therefor, there is provided an optical waveguide member characterized in that an optical waveguide is formed at a portion over a silicon substrate, a core or a clad of the optical waveguide comprises a polymer resin, a groove in a shape of V for positioning and fixing an optical fiber to the optical waveguide is provided to the silicon substrate and a groove in a rectangular shape extended in a direction orthogonal to the groove in the shape of V at a boundary of the V-groove and the optical waveguide, is provided to the silicon substrate, a film thickness of the core or the clad constituting the optical waveguide becomes thinner at a vicinity of the boundary than a film thickness of other portion and the shape of the groove having the shape of V is set such that when the optical fiber is mounted to the V-groove in the shape of V, a height of a center of a core of the optical fiber becomes lower than a height of the core of the optical waveguide at a position sufficiently remote from the boundary and highly efficient optical coupling is achieved between the optical fiber and the optical waveguide.