Studying the universality of field induced tunnel ionization times via high-order harmonic spectroscopy

摘要: High-harmonics generation spectroscopy is a promising tool for resolving electron dynamics and structure in atomic molecular systems. This scheme, commonly described by the strong field approximation, requires deep insight into basic mechanism that leads to harmonics generation. Recently, we have demonstrated ability resolve first stage of process -- induced tunnel ionization adding weak perturbation fundamental field. Here generalize this approach show assumptions behind approximation are valid over wide range conditions. Performing systematic study modifying wavelength, intensity system observed good agreement with quantum path analysis Keldysh parameters. The generality scheme opens new perspectives high spectroscopy, holding potential probing large, complex