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Coherent nonlinear spectroscopy in the EUV regime (CHOISE)

Coherent nonlinear spectroscopy in the EUV regime (CHOISE)

CHOISE

Time-resolved coherent nonlinear spectroscopy is a powerful approach to study the ultrafast dynamics and structure of complex quantum systems. They offer high temporal and spectral resolution and are ideal to study quantum coherences, molecular couplings and related ultrafast dynamics. While these methods are well established in the infrared to visible wavelength range, their transfer to the extreme ultraviolet (XUV) regime is a major goal in ultrafast spectroscopy for two reasons: with XUV light sources, much shorter laser pulses reaching into the attosecond regime can be produced. This is impossible at visible wavelengths, and would thus improve temporal resolution to a new level. As a second advantage, with XUV photon energies, electrons in strongly localized inner-shell orbitals can be probed, which provides a highly spatially localized observable to probe molecular dynamics in complex systems.
To facilitate this development, we have established a unique technique capable of providing interferometric timing and phase control of XUV pulse trains, which sets the basis for coherent nonlinear XUV spectroscopy [1]. In a BMBF-funded research project we now explore the possibilities to extend this approach to high photon energies where inner-shell states can be accessed using seeded Free Electron Lasers (FELs). Furthermore, in a DFG-funded collaboration with the group of G. Sansone, University of Freiburg, we develop coherent two-dimensional XUV spectroscopy and nonlinear attosecond spectroscopy schemes with a High Harmonic Generation (HHG) laser source. Our experiments focus on the study of coherent wave packet dynamics, attosecond metrology and two-color VIS-XUV two-dimensional electronic spectroscopy of fundamental systems such as atoms, atomic clusters and small molecules.

This work is also part of the ERC advanced grant "Coherent multidimensional spectroscopy of controlled isolated systems (COCONIS)".

XUV-Coherence

Figure 1: Tracking the electronic coherence of an inner-subshell-valence superposition with XUV wave packet interferomtery [1]. a) Excitation scheme in argon atoms. b) Observed attosecond electronic coherences. c) Measurements were performed at the Free Electron Laser facility FERMI in Trieste, Italy.

 

Relevant publications:

[4]Wituschek A, Bruder L, Allaria E, Bangert U, Binz M, Borghes R, Callegari C, Cerullo G, Cinquegrana P, Gianessi L, Danailov M, Demidovich A, Di Fraia M, Drabbels M, Feifel R, Laarmann T, Michiels R, Mirian N S, Mudrich M, Nikolov I, O'Shea F H, Penco G, Piseri P, Plekan O, Prince K C, Przystawik A, Ribič P R, Sansone G, Sigalotti P, Spampinati S, Spezzani C, Squibb R J, Stranges S, Uhl D, Stienkemeier F:
Tracking attosecond electronic coherences using phase-manipulated extreme ultraviolet pulses
Nat Commun, 2020; 11 (803): 1-7.: abstract - pdf - arXiv

[3] Wituschek A, Bruder L, Klein L, Strucka J, Demidovich A, Danailov M B, Stienkemeier F:
Stable interferometric platform for phase modulation of seeded free-electron lasers
Opt Lett, 2019; 44 (4): 943-946.: abstract - pdf

[2
] Bruder L, Binz M, Stienkemeier F:
Phase-synchronous undersampling in nonlinear spectroscopy
Opt Lett, 2018; 43 (4): 875-878.: abstract - pdf - arXiv

[1] Bruder L, Bangert U, Stienkemeier F:
Phase-modulated harmonic light spectroscopy
Opt Express, 2017; 25 (5): 5302-5315.: abstract - pdf

 

 

Contact:

Dr. Lukas Bruder, lukas.bruder[at]physik.uni-freiburg.de

 

Funding:

Deutsche Forschungsgemeinschaft

European Research Council

Bundesministerium für Bildung und Forschung

International Research Training Group (IRTG 2079) "Cold Controlled Ensembles in Physics and Chemistry"

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