Time-resolving the birth of photoelectrons in strong-filed ionization with an isolated attosecond pulse

TL;DR

This paper proposes a theoretical scheme using isolated attosecond pulses to directly recover the phase of emitted electronic wave packets, enabling time-resolved observation of photoelectron birth processes in strong-field ionization.

Contribution

It introduces a novel method to retrieve photoelectron spectral phase without perturbing the ionization process, advancing ultrafast measurement techniques.

Findings

Full recovery of photoelectron spectral phase from observable spectra.

Revealed the time and energy relationship during photoelectron birth.

Demonstrated the scheme's potential for investigating electronic dynamics.

Abstract

To time-resolve attosecond electronic dynamics in general photoionization processes, the technique that retrieves the phase of emitted electronic wave packets without intercepting the interactions is essential. Here, we theoretically demonstrate a scheme that uses isolated attosecond pulses (IAPs) to achieve this goal. Our approach utilizes the coherent interference between the electronic wave packets of interest and the one produced by a subsequent IAP. It is shown that the photoelectron spectral phase that has eluded direct detection so far can be fully recovered from observable photoelectron spectra without perturbing the electron-release process under investigation. By further performing a time-frequency-like analysis on the photoelectron energy spectra with the spectral phase, we reveal the birth processes of photoelectrons in time and the association between electronic energy and birth time in strong-field ionization driven by circularly polarized laser pulses. The present work explores a promising application of IAPs for ultrafast measurement and opens a viable venue for investigating electronic dynamics with quantum phase information.