Patent ID: 9116368
Filing Date: 2015-08-25
Classification: G02B,G02F,H04B,H04L

Abstract:
1. An optical modulation device, comprising: an I-component optical modulation unit that modulates a continuous optical signal for an I-component of a QAM signal; a Q-component optical modulation unit that modulates a continuous optical signal for a Q-component of the QAM signal; a phase shift unit that shifts a phase of an optical signal on an input side and/or an output side for the I-component optical modulation unit and/or the Q-component optical modulation unit to adjust a phase difference between an output of the I-component optical modulation unit and an output of the Q-component optical modulation unit after the phase shift to π/2; a QAM signal generation unit that multiplexes the output of the I-component optical modulation unit and the output of the Q-component optical modulation unit after the phase shift to generate the QAM signal; an I-component data signal output unit that outputs an I-component data signal to the I-component optical modulation unit to cause the I-component optical modulation unit to modulate a continuous optical signal using the I-component data signal; a Q-component data signal output unit that outputs a Q-component data signal to the Q-component optical modulation unit to cause the Q-component optical modulation unit to modulate a continuous optical signal using the Q-component data signal; an I-component bias voltage signal output unit that outputs a signal having an I-component bias voltage corresponding to a null point of the I-component optical modulation unit to the I-component optical modulation unit; a Q-component bias voltage signal output unit that outputs a signal having a Q-component bias voltage corresponding to a null point of the Q-component optical modulation unit to the Q-component optical modulation unit; an I-component bias voltage signal adjustment unit that: a Q-component bias voltage signal adjustment unit that: