Grebing, C.C.GrebingMüller, M.M.MüllerBuldt, J.J.BuldtStark, H.H.StarkLimpert, J.J.Limpert2022-03-062022-03-062020https://publica.fraunhofer.de/handle/publica/26586710.1364/ol.408998We demonstrate the reliable generation of 1-mJ, 31-fs pulses with an average power of 1 kW by post-compression of 200-fs pulses from a coherently combined Yb:fiber laser system in an argon-filled Herriott-type multi-pass cell with an overall compression efficiency of 96%. We also analyze the output beam, revealing essentially no spatiospectral couplings or beam quality loss.enaverage powercompression efficiencylaser systemMillijoule pulsemultipass cell620535journal article