| 摘要 |
A light modulation element configured from a substrate-type optical waveguide is provided with: a light incidence part through which light is incident on the substrate-type optical waveguide; a Mach-Zehnder interferometer comprising a first light branching part which branches the light incident on the light incidence part, two arm parts which guide the light branched by the first light branching part, a phase modulation part which is linearly provided in at least one of the two arm parts, and a first light multiplexing part which multiplexes the light guided from the two arm parts; a light emission part which emits the light multiplexed by the first light multiplexing part from the substrate-type optical waveguide; and a traveling wave electrode which has an input part and an output part and applies voltage to the phase modulation part. The substrate-type optical waveguide has an outline including two sides each crossing an extension line in the longitudinal direction of the phase modulation part in plan view, the input part is formed in one of the two sides, and the light incidence part and the light emission part are each located in a region different from a region in which the traveling wave electrode is formed in plan view. |
