Real-time In-field Automatic Bias Control and Self-calibration Module for High-baud Coherent Driver Modulator

We report a real-time in-field low-cost module that can simultaneously realize self-calibration and automatic-bias-control for coherent driver modulators. Precise frequency-response (<0.5dB) and IQ skew (<0.2ps) correction are achieved in experiments of 25/20GBaud 16/64QAM signal transmissions.