Phase dependence of intense-field ionization

Publisher Website
Google Scholar
Abstract
Two-color radiation has been used to investigate the physical mechanism of intense-field ionization. One color was the second harmonic of the other, and there was a well-defined phase between them which was calibrated absolutely. We measured the photoelectron yield from above-threshold ionization of krypton and xenon as this phase was varied. We show that the phase-dependent signature of tunnel ionization is present even though the electron spectra are clearly multiphoton in character. We also use the two-color phase as a probe to show evidence for core scattering during the ionization process. © 1996 The American Physical Society.