Abstract

Currently, an isolated attosecond pulse, particularly in the water window region, from the high harmonic generation (HHG) driven by a few-cycle short wavelength infrared (SWIR) laser source had been one of the most exciting research topics in ultrafast laser science. According to the cutoff law of HHG, it was evident that a driving laser with a longer wavelength was the essential requirement for extending the cutoff photon energy through the ponderomotive scaling. Previous, based on the dual-chirped optical parametric amplification (DC-OPA) and type-I BiB3O6 (BiBO) crystals, the generation of 102 mJ, 10.4 fs (2-cycle@1.7 µm), 10 Hz, carrier-envelope phase (CEP)-stable SWIR pulse was demonstrated producing a peak power of 10 TW [1]. In this paper, we further demonstrate the short pulse duration which reaches a single-cycle via novel amplification methods. Based on our previous research [2], we employ the advanced DC-OPA scheme, which consists of two kinds of nonlinear crystals (MgO:LiNbO₃ + BiBO).

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