| abstract |
An optical modulator comprises a substrate (1) having a region (17a) where the polarization is not inverted and a region (17b) where the polarization is inverted and an optical waveguide (18) having first and second optical waveguides (18a, 18b), where an interaction section where the light propagating through first and second optical waveguides and an electric signal propagating through a traveling wave electrode composed of center conductor (19a) and grounding conductors (19b, 19c) interact with each other includes first and second interaction section (20a, 20b) polarized in mutually different directions, the center conductor is opposed to the first and second optical waveguides in the respective first and second interaction sections, and the phase of the light propagating the first and second optical waveguides is modulated in the first and second interaction sections. In the optical modulator, an optical waveguide shift section (20c) is provided between the first and second interaction sections, and the relative positions of the center conductor, the grounding conductor, and the first and second optical waveguides are interchanged in the first and second interaction sections. |