2011/02/28 by J. M. Dahlström, A. L'Huillier, J. Mauritsson · 2 citations
Physics and Astronomy · #quant-ph #physics.atom-ph #physics.optics
paper · pdf · doi:10.1088/0953-4075/44/9/095602
published as J. Phys. B: At. Mol. Opt. Phys. 44 (2011) 095602
arxiv created 2011/03/17 · arxiv updated 2015/03/18
We investigate the generation of even and odd harmonics using an intense laser and a weak second harmonic field. Our theoretical approach is based on solving the saddle-point equations within the Strong Field Approximation. The phase of the even harmonic oscillation as a function of the delay between fundamental and second harmonic field is calculated and its variation with energy is found to be in good agreement with recent experimental results. We also find that the relationship between this phase variation and the group delay of the attosecond pulses, depends on the intensity and wavelength of the fundamental field as well as the ionization potential of the atom.