Hybrid genetic-algorithm-based design of RF-power-efficient spectrally flat electro-optic frequency combs

We propose a hybrid genetic algorithm-based approach for estimating the optimal modulator drive parameters needed to achieve maximum spectral flatness for a target number of lines in GHz-repetition-rate electro-optic frequency combs (EOFCs), while adhering to specified RF power constraints. We present both simulation results and experimental validation using a dual-parallel Mach–Zehnder modulator (DPMZM) and a cascaded dual-drive Mach–Zehnder modulator (DDMZM)-DPMZM architecture at telecom wavelengths near ∼1550nm. Using the DPMZM, we generate seven comb lines with <2dB flatness, and using the DDMZM-DPMZM cascade, we achieve 13 comb lines within 3.5 dB of flatness, all realized using 10 GHz drive with RF voltages ≤V π at each modulator port.