Müller, M.M.MüllerAleshire, C.C.AleshireStark, H.H.StarkBuldt, J.J.BuldtSteinkopff, A.A.SteinkopffKlenke, A.A.KlenkeTünnermann, A.A.TünnermannLimpert, J.J.Limpert2022-03-142022-03-142020https://publica.fraunhofer.de/handle/publica/40800610.1117/12.2546857We present a coherently-combined ultrafast fiber laser system consisting of twelve amplifier channels delivering 10.4 kW average power at 80 MHz repetition rate with a pulse duration of 240 fs FWHM and an almost diffraction-limited beam quality of M2 < 1.2. The system incorporates an automated self-adjustment of the beam combination with 3 degrees of freedom per channel. The system today is, to the best of our knowledge, the world's most average-powerful femtosecond laser. Thermographic analysis indicates that power scaling to 100 kW-class average power is feasible.en620conference paper