Generation of 48 fs, 1 GHz Fundamentally Mode-Locked Pulses Directly from an Yb-doped “Solid-State Fiber Laser”

We demonstrate a fundamentally mode-locked Yb-doped “solid-state fiber laser” with a repetition rate of 1 GHz and a pulse duration of 48 fs. The nonlinear-polarization-evolution (NPE) mode-locking of the “solid-state fiber laser” enables up to 286 mW of average power and a 26 nm spectrum bandwidth, which supports a 48 fs pulse duration. The laser self-starts and the central wavelength can be tuned from 1032.4 nm to 1035.6 nm. To the best of our knowledge, it is the shortest pulse duration directly obtained by GHz fundamentally mode-locked Yb-fiber lasers.