Elahi, P.Akçaalan, Ö.Ertek, C.Eken, K.İlday, Fatih ÖmerKalaycoglu, H.2019-02-212019-02-2120180146-9592http://hdl.handle.net/11693/50388We report on a 72 W Yb all-fiber ultrafast laser system with 1.6 GHz intra-burst and 200 kHz burst repetition rate developed to demonstrate ablation-cooled material removal at high speeds. Up to 24 W is applied on Cu and Si samples with pulses of ~300 fs, and record-high ablation efficiencies are obtained, compared to published results to date, despite using only ~100 nJ pulses. Ablation speeds approaching 1 mm3∕s are reported with 24 W of average power, limited by available laser power and beam scanning speed. More significantly, these results experimentally confirm the theoretically expected linear scaling of the ablation-cooled regime to higher average powers without sacrificing efficiency, which implies that further scaling is possible with further increases in laser power and scanning speeds.EnglishArticle10.1364/OL.43.000535