Optical transmission apparatus

摘要

A first clock modulator branches a light beam, varies a phase difference of the resulting light beams according to a first clock, and causes interference of the light beams. A second clock modulator branches a light beam from the first clock modulator and synchronized with the first clock, varies a phase difference of the resulting light beams according to a second clock, and causes interference of the light beams. A third clock modulator branches a light beam from the first clock modulator and inversely synchronized with the first clock, varies a phase difference of the resulting light beams according to a third clock, and causes interference of the light beams. The second clock and the first clock have identical cycles and differing phases. The third clock and the second clock have phases that differ by a 1/2 cycle. Four data modulators modulate the light beams from the clock modulators.

主权项

1. An optical transmission apparatus comprising:
a generating unit that generates a first clock signal, a second clock signal of a cycle identical to that of the first clock signal and a phase different from that of the first clock signal, and a third clock signal of a phase different from that of the second clock signal by a 1/2 cycle; a first optical modulator that branches a light beam input thereto, changes a phase difference of resulting light beams according to the first clock signal, and causes interference of the light beams having the changed phase difference; a second optical modulator that branches a light beam synchronized with the first clock signal among the light beams obtained from the first optical modulator, changes a phase difference of resulting light beams according to the second clock signal, and causes interference of the light beams having the changed phase difference; a third optical modulator that branches a light beam inversely synchronized with the first clock signal among the light beams obtained from the first optical modulator, changes a phase difference of resulting light beams according to the third clock signal, and causes interference of the light beams having the changed phase difference; an optical modulating unit that executes modulation based on the light beams obtained from the second optical modulator and the third optical modulator, respectively, and a drive signal input thereto; and an optical coupler that combines optical signals obtained by the modulation executed by the optical modulating unit.