Subpicosecond SESAM and nonlinear polarization evolution hybrid mode-locking ytterbium-doped fiber oscillator

We report on a high-power 960-fs subpicosecond pulse generation from a passively mode-locked ytterbium-doped large-mode-area photonic crystal fiber oscillator in the all-normal dispersion regime. Stable and self-starting operation is obtained by exploiting an efficient combination of a high modulation depth semiconductor saturable absorber mirror and the nonlinear polarization evolution mode-locking mechanism. In the single-pulse regime, the laser directly generates the output power of 3.15 W at the repetition rate of 83.7 MHz, corresponding to the pulse energy of 37 nJ. The center wavelength is 1,030 nm with the spectral bandwidth of 8 nm at the maximum output power. The output characteristics of the oscillator are discussed carefully.