| 摘要 |
The objective is to provide an optical modulator with which it is possible to prevent lowering of the frequency band when a light-receiving element is arranged on a substrate forming a light modulator, and two light beams emitted from a multiplexing unit for Mach-Zehnder type optical waveguides are simultaneously received and monitored. This optical modulator has a substrate (1), an optical waveguide that include Mach-Zehnder type optical waveguides formed on the substrate, and a modulation electrode (not shown in the figure) for modulating the light waves propagated through the waveguide. This optical modulator is characterized in that a light-receiving element (5) is arranged so as to straddle an output waveguide (24) forming the Mach-Zehnder type optical waveguides, and is configured so as to receive two light beams emitted from a multiplexing unit for the Mach-Zehnder type optical waveguides, with two or more light-receiving parts (51, 52) being formed separated from each other on one light-receiving element substrate (55) in the light-receiving element. |
