Optical waveguide device, manufacturing method therefor, optical modulator, polarization mode dispersion compensator, and optical switch
An optical waveguide device includes: a substrate which has an electro-optical effect; an optical waveguide which is formed on the substrate and/or inside the substrate; and an in-substrate electrode which is formed of a metal and provided inside the substrate.
1. A method comprising:
forming an optical waveguide on a substrate and/or inside the substrate, the substrate having an electro-optical effect;
forming an in-substrate electrode of metal inside the substrate;
arranging a signal electrode over the optical waveguide; and
arranging a ground electrode over a first surface of the substrate and separated by a distance from the signal electrode;
forming a via hole; and
creating a connection between the ground electrode and the in-substrate electrode through a via-hole provided in the substrate.
2. The method according to claim 1 , the method further comprising:
condensing and radiating an ultrashort pulse laser onto a part of the substrate where the in-substrate electrode is to be formed, and selective etching after the part is amorphized or performing ablation on the part.
3. The method according to claim 1 , wherein forming the in-substrate electrode includes
forming a cavity within the substrate; and
filling the cavity with the metal to form the in-substrate electrode.