Schreiber, T.T.SchreiberOrtac, B.B.OrtacNielsen, C.K.C.K.NielsenLimpert, J.J.LimpertTünnermann, A.A.Tünnermann2022-03-102022-03-102006https://publica.fraunhofer.de/handle/publica/35139310.1117/12.646168We report on a high power, high-energy femtosecond fiber source based on direct amplification of parabolic pulses from an environmental stable passively mode-locked fiber oscillator in an Yb-doped single-polarization photonic crystal fiber. The system delivers a pulse energy of 1.2 ?J (21 W average power) at a repetition rate of 17 MHz and a pulse duration of 240 fs in a linearly polarized beam with diffraction-limited quality. The special pulse shape allows for the generation of high quality femtosecond pulses beyond nonlinearity limits, which is confirmed by numerical simulations.enfemtosecond pulse generationFiber optic amplifier and laser620conference paper