Efficient generation of an isolated single-cycle attosecond pulse

TL;DR

This paper proposes a new method combining UV and IR pulses to efficiently generate isolated single-cycle attosecond pulses, enhancing harmonic yields and controlling electron wave packet dynamics.

Contribution

A novel approach using UV and IR pulse timing to produce isolated attosecond pulses with improved efficiency and control over quantum trajectories.

Findings

Successfully generated a 130-as isolated pulse with 45 eV bandwidth.

Enhanced harmonic and attosecond pulse yields compared to previous schemes.

Achieved potential for sub-100 as single-cycle attosecond pulses.

Abstract

A new method for efficiently generating an isolated single-cycle attosecond pulse is proposed. It is shown that the ultraviolet (UV) attosecond pulse can be utilized as a robust tool to control the dynamics of electron wave packets (EWPs). By adding a UV attosecond pulse to an infrared (IR) few-cycle pulse at a proper time, only one return of the EWP to the parent ion is selected to effectively contribute to the harmonics, then an isolated two-cycle 130-as pulse with a bandwidth of 45 eV is obtained. After complementing the chirp, an isolated single-cycle attosecond pulse with a duration less than 100 as seems achievable. In addition, the contribution of the quantum trajectories can be selected by adjusting the delay between the IR and UV fields. Using this method, the harmonic and attosecond pulse yields are efficiently enhanced in contrast to the scheme [G. Sansone {\it et al.}, Science {\bf314}, 443 (2006)] using a few-cycle IR pulse in combination with the polarization gating technique.