Rothhardt, J.J.RothhardtHädrich, S.S.HädrichKlas, R.R.KlasTadesse, G.K.G.K.TadesseHoffmann, A.A.HoffmannTschernajew, M.M.TschernajewKlenke, A.A.KlenkeVárallyay, Z.Z.VárallyayDrozdy, A.A.DrozdyCormier, E.E.CormierLiem, A.A.LiemSchreiber, T.T.SchreiberLimpert, J.J.LimpertTünnermann, A.A.Tünnermann2022-03-132022-03-132015https://publica.fraunhofer.de/handle/publica/39399010.1364/ASSL.2015.ATu4A.22-s2.0-84947598814Double-stage nonlinear compression of state-of-the-art femtosecond fiber lasers allows for few-cycle lasers with record-high average power levels. Here, a comprehensive study on further power scaling aspects is presented. Compression to sub-2cycle pulses is demonstrated and it is shown that capillary waveguides and gold-coated sapphire optics are suitable to realize several 100 W of average power in combination with energetic sub-2cycle pulses in the near future. These lasers could open unique possibilities in high harmonic generation and attosecond science.enconference paper