Patent ID: 8467635

Claim:
A Mach-Zehnder optical modulator of an optical waveguide type, comprising: a heater provided on at least one of first arm waveguides made of a non-electro-optic material; and electrodes provided on second arm waveguides made of an electro-optic material having an electro-optic effect, the second arm waveguides being optically connected to the first arm waveguides, wherein the heater is configured to set an operating point of the optical modulator by adjusting a phase of at least one of the first arm waveguides, and the electrodes are configured to apply a modulating signal for the optical modulator, wherein a substrate of the non-electro-optic material and a substrate of the electro-optic material are joined with an adhesive agent having a lower thermal conductivity than that of the substrate of the electro-optic material.