Ultra-flat optical frequency comb generator using a single-driven dual-parallel Mach-Zehnder modulator

We propose and experimentally demonstrate a simple and cost-effective ultra-flat optical frequency comb (OFC) generator by directly modulating a standalone dual-parallel Mach-Zehnder modulator (DP-MZM) with only one radio frequency (RF) signal without any other assisting devices. Five- and seven-tone OFC with exactly the same intensity can be theoretically generated using two sets of parameters obtained by solving equations derived from the DP-MZM modulation model. In good agreement with the theoretical results, five- and seven-tone OFC with flatness of 0.1 and 1 dB are experimentally demonstrated, respectively.