Patent ID: 8977119
Filing Date: 2015-03-10
Classification: H04B

Abstract:
1. An automatic bias control apparatus for optical transmitter, comprising: a detecting unit configured to monitor output optical power of an I/Q modulator of the optical transmitter; a calculating unit configured to calculate respective bias voltage indicating values of the I modulator, Q modulator and phase modulator of the I/Q modulator according to the output optical power and known modulation data; and an adjusting unit configured to adjust respectively Direct-Current (DC) bias voltages of the I modulator, Q modulator and phase modulator according to the respective bias voltage indicating values of the I modulator, Q modulator and phase modulator; wherein the calculating unit comprises: a sign extracting module configured to extract the sign of I modulation data of the I/Q modulator, the sign of Q modulation data of the I/Q modulator, and the sign of a product of the I modulation data and the Q modulation data; and a calculating module configured to calculate respectively the bias voltage indicating values of the I modulator, Q modulator and phase modulator according to the output optical power, the sign of the I modulation data, the sign of the Q modulation data and the sign of the product of the I modulation data and the Q modulation data.