Comb Line Multiplication in an InP Integrated Photonic Circuit Based on Cascaded Modulators

We report the broadband characterization of an indium phosphide monolithically integrated optical frequency comb generator based on cascaded modulators. The device consists of a dual-drive Mach-Zehnder modulator (MZM), two cascaded phase modulators, and is also equipped with an integrated laser source, resulting in an extremely compact device, tunable both in wavelength and comb line frequency. Co...