Flat Frequency Comb Generation With an Integrated Dual-Parallel Modulator

A dual-parallel Mach-Zehnder modulator is employed to generate an optical frequency comb. Flat spectral response is obtained by optimizing the dc bias and the RF drive parameters of the device which is driven in the gigahertz frequency range. We demonstrate theoretically and experimentally, a flat spectral output across nine sidebands. A tunable multiwavelength source based on this approach allows for very precise wavelength spacing for dense wavelength-division-multiplexing applications and has the advantages of efficiency and simplicity.