From In-Situ Sub-Cycle Pulse Characterization to Quantitative in Silico High-Harmonic Generation Predictions

High-harmonic generation (HHG) driven with few-cycle infrared pulses has long been one of the fundamental enablers of attosecond science, since it allows one to build tabletop pump-probe experiments with isolated XUV or soft X-ray attosecond pulses. When pushing the infrared driving pulse duration to the single and sub-cycle regime, one naturally produces isolated attosecond pulses (IAPs) more easily because the HHG process occurs within a single optical cycle. However, it is still under debate how to maximize the efficiency of IAPs in a given spectral range considering all the experimental parameters. In particular, it is crucial to precisely characterize the fields used experimentally because of their complex non-sinusoidal shapes, necessary to accurately simulate the experimental results and understand the mechanisms of efficiency enhancement and IAP production.