All-fiber frequency-agile triple-frequency comb light source

Abstract

We experimentally demonstrate a novel approach to generate a multi-frequency comb light source with a high mutual coherence in an all-fiber system. Starting from EOM combs, we exploit spatial light multiplexing in a 3-core all-normal nonlinear silica fiber at 1550 nm. Each pulse propagates in its own core to experience a nonlinear broadening but within the same fiber. We obtained 3 almost similar output flat-top spectra spanning over 14 nm with 3 nJ per pulse at 250 MHz and a flat phase noise spectrum down to -125 dBc/Hz. The signal-to-noise ratio of interferograms is about 40 dB.