2.2 Ultrafast Molecular Dynamics

Project coordinators: A. Rouzée , K. Amini

T3: Strong field excitation and HHG in tailored fields

Part of Project 2.2 is dedicated to advancing the generation of attosecond pulses with controlled polarization. We have carried out an extensive series of studies on high-harmonic generation (HHG) dynamics in two-color, bi-circular (TCBC) driving schemes employing tailored fields with frequency ratios of ω/2ω, ω/3ω, and ω/4ω in the 400–1600 nm spectral range. These efforts culminated in the demonstration of a novel scheme for producing isolated attosecond pulses with high ellipticity, together with the full characterization of their polarization state (U. Bengs, N. Zhavoronkov, Scientific Reports11, 9570)

Fig: (A) TCBC approach: femtosecond driving radiation with opposite helicity and multiple frequencies, (B) XUV-chiral continuum generated with few cycles w-2w driving radiation, (C) temporal shape of the chiral HHG pulse evaluated for the spectrum on the position of white dashed line in (B).

Fig.: (A) Origin of the Stückelberger oscillations. Energy of the Rydberg state follows the instantaneous field intensity I. (B) Radiation originate from FID of excited states associated with spin-orbit components of the Ar+ ion (2P1/2 and 2P3/2), (C) results of the volume-averaged simulations for the two-level atom model (colour lines) and TDSE (black line).

Another new approach was developed in a frame of high harmonic spectroscopy to recover the electronic state population dynamics of strongly driven Rydberg states by all-optical measurements in terms of Stückelberg spectroscopy. Combining the experimental results with accurate numerical simulations and a simple model we demonstrate the potential of this art of spectroscopy to characterize lifetimes of Rydberg states dressed by laser fields with strengths far exceeding the Coulomb field between the Rydberg electron and the core (U.Bengs, N, Zhavoronkov et. al.,Phys. Rev. Res.., 4, 023135 (2022)).

People involved:

Nickolai Zhavoronkov, Misha Ivanov

Search publications of MBI

Search results

Publications since 2026

Sort: Year Author Title Journal

A3-P-2026.01

Apparatus for broadband, time-resolved measurements of laser-induced reflectivity transients with sub-10 fs resolution

H. M. Wrigge, T. Held, P. D. Ndione, T. Nagy, B. Rethfeld, P. Simon

Optics & Laser Technology 193, Part B (2026) 114354/1-8

URL, DOI or PDF

Overview MBI-Projects Overview Topics