Autoionizing States driven by Stochastic Electromagnetic Fields

TL;DR

This paper investigates how stochastic electromagnetic fields influence autoionizing resonances, revealing significant profile distortions driven by pulse duration and field fluctuations, with implications for ultrafast spectroscopy.

Contribution

It introduces a stochastic differential equation approach to analyze autoionizing states under short, moderate fields, emphasizing the impact of pulse duration and field fluctuations.

Findings

Strong profile distortion even below strong field limit

Pulse duration significantly affects resonance profiles

Field fluctuations play a crucial role in resonance behavior

Abstract

We have examined the profile of an isolated autoionizing resonance driven by a pulse of short duration and moderately strong field. The analysis has been based on stochastic differential equations governing the time evolution of the density matrix under a stochastic field. Having focused our quantitative analysis on the $2s2p({}^1P)$ resonance of Helium, we have investigated the role of field fluctuations and of the duration of the pulse. We report surprisingly strong distortion of the profile, even for peak intensity below the strong field limit. Our results demonstrate the intricate connection between intensity and pulse duration, with the latter appearing to be the determining influence, even for a seemingly short pulse of 50 fs. Further effects that would arise under much shorter pulses are discussed.