TRAVELING WAVE OPTICAL MODULATOR

An object of the invention is to provide a traveling-wave-type optical modulator capable of adjusting the frequency characteristics of an electric/optical conversion response over a wide frequency band, preventing the occurrence of jitter, and improving optical transmission characteristics.A traveling-wave-type optical modulator 20 includes: a substrate that has an electro-optical effect; an optical waveguide that is formed on the substrate; a modulating electrode that controls the modulation of a light wave traveling through the optical waveguide and includes a signal electrode portion 21 and a ground electrode portion; an input interface 22 that is connected to an input side of the signal electrode portion; a terminator 23 that is connected to the end of the signal electrode portion; and an adjustment filter 31 that is provided between the input interface and the signal electrode portion and adjusts frequency characteristics.It is preferable that the adjustment filter 31 be a passive filter.