Generation of sub-30 fs pulses from an erbium-doped fiber amplifier at 203 MHz repetition rate

Abstract High repetition rate fiber lasers have attracted great attention in recent years due to their potential applications including spectroscopy and laser processing. In this manuscript, we have demon-strated sub-30 fs pulses directly from a compact Er-doped fiber laser amplifier system with a high repetition rate of ∼203 MHz. The design of the laser comprises of a home-built oscillator based on nonlinear polarization evolution mode-locking mechanism, an all-fiber amplifier, and a fiber type compressor. By optimizing the length of single mode fiber compressor, the shortest pulse duration of 26 fs is achieved, which is ∼4.9 optical cycle at 1570 nm. The average output power of the de-chirped pulse is 267 mW with corresponding pulse energy of 1.3 nJ. Such a high repetition rate fiber laser with few-cycle pulse holds tremendous potential for numerous applications that require high temporal resolution, and high photon flux.