Investigation of transient surface electric field induced by femtosecond laser irradiation of aluminum

TL;DR

This study directly measured transient electric fields on aluminum surfaces induced by femtosecond laser pulses, revealing their duration, strength, and potential impact on ultrafast electron techniques.

Contribution

It provides the first direct measurement and analysis of femtosecond laser-induced surface electric fields on aluminum using ultrashort electron pulses.

Findings

Transient fields last at least one nanosecond.

Maximum field strength reaches 5.3 x 10^4 V/m.

A three-layer model explains the fields and photoelectron evolution.

Abstract

Transient surface electric fields induced by femtosecond laser irradiation of an aluminum film were investigated directly by ultrashort electron pulses. At pump intensities of 2.9~7.1 * 10^10 W/cm2, the transient electric fields last at least one nanosecond with a maximum field strength of 3.2~5.3 * 10^4 V/m at 120 micro m above the aluminum surface. The transient electric fields and the associated evolution of photoelectrons were explained by a "three-layer" model. The potential influence of such fields on reflection ultrafast electron diffraction and time-resolved angle-resolved photoemission spectroscopy were evaluated.