Pre-distortion technique for compensating QAM signal distortions generated by dual-parallel Mach-Zehnder modulators with low-extinction ratio and small-chirp parameter

Abstract

We propose a pre-distortion method in the electrical domain to compensate for IQ-distortion that is attributed to some imbalances of dual-parallel Mach-Zehnder modulators for optical QAM. We confirmed the effect of the method by performing calculations, and the calculation results show the potential to improve the signal quality.