Resolving XUV induced femtosecond and attosecond dynamics in polyatomic molecules with a compact attosecond beamline

V Loriot,I Compagnon,F Lépine,L Quintard,B Schindler,B Concina,G Celep,F Catoire,C Bordas,A Marciniak,E Constant,V Despré

doi:10.1088/1742-6596/635/1/012006

Abstract

XUV induced dynamics in molecules is still largely unexplored while experimental and theoretical tools are becoming available in several labs. In this work, we present a compact XUV beamline designed to induce and probe femtosecond and attosecond dynamics in gas samples (from atoms to complex molecular species). The induced processes are studied with time-resolved photoelectron or/and photoion imaging. The characterization of the performances of the experimental setup is presented. We show experimental results obtained in naphthalene molecule showing femtosecond and attosecond time-resolved photoelectron imaging experiments allowing electron wavepacket phase measurements.

Highlights

Attoscience is a rapidly expanding field of research that explores physical processes associated with electron dynamics in atoms, molecules and surfaces [1]
The pump-probe configuration developed here is shown in figure 1. It is composed by a long interferometer placed on an independent optical table seeded by 25 fs long pulses at λ0 ≈ 807 nm, 2 mJ with 5 kHz repetition rate delivered by a commercial amplifier laser system (Coherent elite duo USX) coupled to a Velocity Map Imaging (VMI) spectrometer
Only the few lowest harmonics significantly contribute to the spectrum that strongly simplifies the photoelectron distribution allowing to estimate the group of orbitals that are important in the experiment

Summary

Introduction

Attoscience is a rapidly expanding field of research that explores physical processes associated with electron dynamics in atoms, molecules and surfaces [1]. By choosing the HHG conditions and using adapted XUV optics, polarization [3], spatial and spectral, amplitude, and phase of the harmonics can be controlled [4]. Nowadays such controlled attosecond pulses are exploited in pump-probe schemes with a delayed infrared pulse, reaching attosecond temporal resolution. XUV photons in attosecond pulses have enough energy to one-photon ionize most of the atomic or molecular species. This ionization step can be used as a probe where the analysis of the resulting photoelectrons provides rich information on the atomic or molecular states involved in the dynamics at a given time.

Methods

Discussion

Conclusion