An Accurate and Robust In-phase/Quadrature Skew Measurement for Coherent Optical Transmitter by Image Spectrum Analyzing

An accurate and robust in-phase/quadrature skew measurement method for coherent optical transmitter based on analyzing the shape of image spectrum is proposed. Experiments under various bias deviations of child/parent Mach-Zehnder modulators demonstrate the standard deviation of measured skew is 0.3ps.