Microwave Photonic PS-Pulse and 140 GHz RF Comb Generator

A microwave photonic RF comb generator is presented by combining an fs-pulse laser and a high-speed broadband photodetector module. The subsystem generates pulses with a FWHM of 5.8 ps and a flat RF comb up to 140 GHz. Furthermore, the capability of pulse distribution over fiber is investigated. The dispersion of the single mode fiber is managed by using an optical bandpass filter, because reducing the optical spectral width limits the pulse broadening. With this scheme, the electrical pulse shape remains constant up to 500 m of fiber transmission. For a demonstration with 1500 m of fiber, the optical bandpass filter dispersion management results in a tradeoff between minimum electrical pulse width and fiber length.