High-power femtosecond Yb-doped single-polarization photonic crystal fiber laser

We report, to the first time to our knowledge, on a passively mode-locked single-polarization single-transverse-mode large-mode-area photonic crystal fiber laser operating in the dispersion compensation free regime. In the single-pulse regime, the laser generates 1.6 W of average power with 3.7 ps pulses at a repetition rate of 63 MHz, corresponding to a pulse energy of 25 nJ. Stable and self-starting operation is obtained by adapting the spot size at the saturable absorber mirror to the pulse evolution in the low-nonlinearity fiber. The pulses are compressible down to 750 fs. The presented approach demonstrates the scaling potential of fiber based short pulse oscillators towards high-power ultra-compact all-fiber environmentally-stable configuration