Patent ID: 7027674

Claim:
An optical module comprising: a carrier on which an optical element is mounted, said carrier being formed of a semiconductor material where a first high-frequency transmission line for transmitting a high-frequency electric signal to the optical element is formed; and a dielectric substrate where a second high-frequency transmission line for supplying a high-frequency electric signal to the first high-frequency transmission line of the carried is formed; wherein: a electrical connection is made between the first high-frequency transmission line and the second high-frequency transmission line by use of a conductor wire; said first high-frequency transmission line is formed of a coplanar waveguide; and said second high-frequency transmission line is formed by coupling a first coplanar waveguide, which is formed on an input side by providing a ground layer under the transmission line across a dielectric, to a second coplanar waveguide formed on an output side with a distance between a signal wiring conductor of the transmission line and the ground layer made longer as compared with the first coplanar waveguide or formed on the output side without providing the ground layer.