Revealing molecular structure and dynamics through high-order harmonic generation driven by mid-IR fields

High-order harmonic generation (HHG) from molecules produces spectra that are modulated by interferencesthat encode both the static structure and the electron dynamics initiated by interaction with the laser field. Usinga midinfrared (mid-IR) laser at 1300 nm, we are able to study the region of the harmonic spectrum containingsuch interferences in CO2 over a wide range of intensities. This allows for isolation and characterization ofinterferenceminima arising due to subcycle electronic dynamics triggered by the laser field, which had previouslybeen identified but not systematically separated. Our experimental and theoretical results demonstrate importantsteps toward combining attosecond temporal and angstrom-scale spatial resolution in molecular HHG imaging