Patent ID: 9063355
Filing Date: 2015-06-23
Classification: G02F,H04B

Abstract:
1. An optical modulation device comprising: a modulation unit that modulates an input light by a drive signal to output an optical signal; a drive unit that applies the drive signal based on a data signal to the modulation unit; and a first bias control unit that performs a bias control to adjust an operating point of a bias voltage of the drive signal such that an optical intensity in a modulation curve of the modulation unit decreases according to a bias voltage value sequentially calculated by the first bias control unit, stops the bias control when the data signal is in a second state different from a first state during the bias control, fixes the bias voltage value to a voltage value at the time of stopping the bias control, continues to supply the bias voltage having the fixed voltage value to the modulation unit during stopping the bias control, and restarts the bias control using the fixed voltage value as an initial value when the data signal returns to the first state from the second state.