Patent ID: 7558444

Claim:
A traveling-wave-type optical modulator, comprising: a substrate that has an electrooptic effect; an optical waveguide that is formed on the substrate; and a modulation electrode that performs modulation control on a light wave propagating through the optical waveguide, wherein a driver for performing driving control on the traveling-wave-type optical modulator is connected to the traveling-wave-type optical modulator, a frequency characteristic of an electro/optical conversion response of the traveling-wave-type optical modulator is adjusted so as to correct a frequency characteristic of a gain of the driver, and in the adjustment of the frequency characteristic of the electro/optical conversion response, when the traveling-wave-type optical modulator is driven by the driver, with respect to an electric signal inputted to the driver, a frequency characteristic of an electro/optical conversion response of an optical signal outputted by the traveling-wave-type optical modulator in a range of frequencies from 300 kHz to 3 GHz is adjusted to be substantially uniform.