eprintid: 29252
rev_number: 15
eprint_status: archive
userid: 5618
dir: disk0/00/02/92/52
datestamp: 2021-01-07 08:55:36
lastmod: 2021-02-01 12:40:17
status_changed: 2021-01-07 08:55:36
type: doctoralThesis
metadata_visibility: show
creators_name: Birk, Paul
title: The Dipole Response of an Ionization Threshold within Ultrashort and Strong Fields
subjects: ddc-530
divisions: i-130001
divisions: i-851340
adv_faculty: af-13
abstract: In this work, the strong-field-modified dipole response at the ionization threshold of helium is studied. The dipole response is induced by an attosecond pulse in the extreme ultraviolet spectral range and is manipulated by an ultrashort and strong femtosecond pulse in the near-infrared. To probe the response, the transient absorption spectrum of helium is recorded for different time delays between both pulses and different intensities of the femtosecond pulse. From the spectra, the dipole response of the ionization threshold is reconstructed, which is linked to the dynamics of excited electrons with energies in the transition region from bound to free. To identify the underlying processes of light-matter interaction leading to the observed structures in the time and spectral domain, different quantum-mechanical model simulations are conducted. As a result, the measured dipole response reveals light-induced energy shifts of the photoelectron’s kinetic energy close to the parent ion, signatures for field-driven recollisions of a photoelectron into the parent ion, and a temporal amplitude and phase gating mechanism. With the latter, the build-up dynamics of complex spectral structures are temporally resolved, which are the time-dependent separation and line-shape modification of the doubly excited Rydberg series as well as the temporal build-up of the ionization threshold.
date: 2020
id_scheme: DOI
id_number: 10.11588/heidok.00029252
ppn_swb: 1746367016
own_urn: urn:nbn:de:bsz:16-heidok-292523
date_accepted: 2020-12-09
advisor: HASH(0x55a9a6408060)
language: eng
bibsort: BIRKPAULTHEDIPOLER2020
full_text_status: public
place_of_pub: Heidelberg
citation:   Birk, Paul  (2020) The Dipole Response of an Ionization Threshold within Ultrashort and Strong Fields.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/29252/1/Dissertation_PaulBirk.pdf