Optical device and optical communication apparatus

An optical communication apparatus comprising:

• a processor that executes signal processing on an electrical signal;
• a light source that generates light;
• and
• an optical device that modulates, by using the electrical signal that is output from the processor, the light generated from the light source, wherein
• the optical device includes
• an input unit that inputs an optical signal,
• a plurality of first silicon (Si) optical waveguides that split and output the optical signal received from the input unit,
• a plurality of LN (LiNbO3) optical waveguides that are included in a LN modulator and that transmit the optical signals that are split and output by the first Si optical waveguides,
• a plurality of second Si optical waveguides that multiplex and output optical signals that are output from the plurality of respective LN optical waveguides,
• an output unit that outputs the optical signal multiplexed by the second Si optical waveguides, and
• a plurality of Mach-Zehnder interferometers that are disposed on optical waveguides connected by the first Si optical waveguides, the LN optical waveguides, and the second Si optical waveguides, respectively, and
• when there are differences among waveguide lengths of the LN optical waveguides, optical waveguides for the respective Mach-Zehnder interferometers are configured so as to equalize optical path lengths by adjusting an effective refractive index and a waveguide length inside at least one of the optical waveguides.