Perturbation-theory analysis of ionization by a chirped few-cycle attosecond pulse

Authors

• Evgeny A. Pronin, University of Nebraska - LincolnFollow
• Anthony F. Starace, University of Nebraska-LincolnFollow
• Liang-You Peng, Peking UniversityFollow

Document Type

Article

Date of this Version

7-22-2011

Comments

Published in PHYSICAL REVIEW A 84, 013417 (2011); DOI: 10.1103/PhysRevA.84.013417 Copyright ©2011 American Physical Society. Used by permission.

Abstract

The angular distribution of electrons ionized from an atom by a chirped few-cycle attosecond pulse is analyzed using perturbation theory (PT), keeping terms in the transition amplitude up to second order in the pulse electric field. The dependence of the asymmetry in the ionized electron distributions on both the chirp and the carrier-envelope phase (CEP) of the pulse are explained using a simple analytical formula that approximates the exact PT result. This approximate formula (in which the chirp dependence is explicit) reproduces reasonably well the chirp-dependent oscillations of the electron angular distribution asymmetries found numerically by Peng et al. [Phys. Rev. A 80, 013407 (2009)]. It can also be used to determine the chirp rate of the attosecond pulse from the measured electron angular distribution asymmetry.