Optical device, optical transmitter, and optical transceiver

An optical transmitter comprising

• a light source that emits light;
• and
• an optical device that modulates the light from the light source according to an electric signal, wherein
• the optical device includes:
• a first chip including a first waveguide and a first electrode;
• and
• a second chip mounted on the first chip and including a second waveguide and a second electrode,
• the second waveguide has an electro-optic effect higher than an electro-optic effect of the first waveguide, has a return structure that places an end of the second waveguide at an end face of the second chip, and is optically coupled to the first waveguide at the end face, and
• the second electrode has a return structure that places an end of the second electrode at the end face, and the second electrode and the first electrode are electrically connected to each other in an area where the end of the second electrode has been placed.

An optical transceiver comprising:

• a processor that executes signal processing of an electric signal;
• a light source that generates light;
• an optical device that modulates the light generated by the light source by using the electric signal output from the processor;
• and
• an optical receiver that converts received light into an electric signal by using the light generated by the light source, wherein
• the optical device includes:
• a first chip including a first waveguide and a first electrode;
• and
• a second chip mounted on the first chip and including a second waveguide and a second electrode,
• the second waveguide has an electro-optic effect higher than an electro-optic effect of the first waveguide, has a return structure that places an end of the second waveguide at an end face of the second chip, and is optically coupled to the first waveguide at the end face, and
• the second electrode has a return structure that places an end of the second electrode at the end face, and the second electrode and the first electrode are electrically connected to each other in an area where the end of the second electrode has been placed.