Single-polarization all-normal-dispersion Yb fiber femtosecond laser with semiconductor saturable absorber mirror operating in two-photon absorption regime

We present a high repetition-rate all-normal-dispersion Yb fiber laser operating in two-photon absorption regime of a SESAM. Ultra-stable pulses with 1 nJ energy, compressed pulse-width of 115.9 fs, and spectral-width of 26 nm are generated.