Abstract
High-order harmonic generation from molecules (, , , and ) and atoms (Xe, Ar, and Kr) has been studied in the few optical cycle domain. Two laser peak intensities; and , were compared. At the lower intensity spectra were approximately the same for molecules and atoms with the same ionization potential, at higher laser intensity the cutoff of and extends far beyond the cutoff of Xe and Kr, respectively, in contrast with and which exhibit cutoffs very close to that of Ar. This behavior is well explained by adopting an atomlike approximation for the molecule response in the high-field regime and employing the Lewenstein’s model, properly modified in order to account for the nonlinear dipole moment of a randomly oriented molecule ensemble.
- Received 3 June 2004
DOI:https://doi.org/10.1103/PhysRevA.71.013409
©2005 American Physical Society