Enhancement of bichromatic high-harmonic generation with a high-frequency field

Abstract

Using a high-frequency field superposed to a linearly polarized bichromatic laser field composed by a wave with frequency $\omega$ and a wave with frequency $2\omega$, we show it is possible to enhance the intensity of a group of high harmonics in orders of magnitude. These harmonics have frequencies about 30% higher than the monochromatic-cutoff frequency, and, within the three-step-model framework, correspond to a set of electron trajectories for which tunneling ionization is strongly suppressed. Particular features in the observed enhancement suggest that the high-frequency field provides an additional mechanism for the electron to reach the continuum. This interpretation is supported by a time-frequency analysis of the harmonic yield. The additional high frequency field permits the control of this group of harmonics leaving all other sets of harmonics practically unchanged, which is an advantage over schemes involving only bichromatic fields.

arXiv comment6 pages RevTex, 5 figures (ps files), Changes in text, figures, references and equations included

References in corpus (1)

• High-harmonic generation from a confined atom

Cited by in corpus (2)

• Isolated sub-100-attosecond pulse generation via controlling electron dynamics
• Exploring symmetries in photoelectron holography with two-color linearly polarized fields