Patent ID: 9599843
Date: 2017-03-21
CPC Classifications: G02F

Claim:
1. An optical modulator comprising: an electro-optic substrate; an optical waveguide; and a modulation electrode including a signal electrode for applying an electric field corresponding to a modulation signal to the optical waveguide, and a ground electrode, wherein the electro-optic substrate includes a trench portion formed by digging a surface of the electro-optic substrate, and a ridge portion formed in a ridge shape by the trench portion so that the optical waveguide is provided, the signal electrode is provided on the ridge portion and is configured so as to be wider than a width of the ridge portion at a cross section in a direction intersecting with a direction of extension of the optical waveguide, the ground electrode is configured so as to reach to a bottom portion of the trench portion, the trench portion includes a first trench portion, which is a trench portion between a pair of branched optical waveguides, and a second trench portion, which is a trench portion other than the first trench portion, digging depths of the first and second trench portions are different, and the optical modulator is a multi-level phase modulator.