Time-resolved investigation of the optical phase change as a potential diagnostics tool for extreme-ultraviolet free-electron-laser pump and optical probe experiments

2019 ◽  
Vol 45 (1) ◽  
pp. 33
Author(s):  
Victor Tkachenko ◽  
Sven Toleikis ◽  
Vladimir Lipp ◽  
Beata Ziaja ◽  
Ulrich Teubner
Keyword(s):  
Phase Change ◽  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Optical Probe ◽  
Time Resolved ◽  
Optical Phase ◽  
Laser Pump

Timing methodologies and studies at the FERMI free-electron laser

2018 ◽  
Vol 25 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Riccardo Mincigrucci ◽  
Filippo Bencivenga ◽  
Emiliano Principi ◽  
Flavio Capotondi ◽  
Laura Foglia ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Electronic Effect ◽  
Extreme Ultraviolet ◽  
Laser Pulses ◽  
Time Resolved ◽  
New Era ◽  
Condensed Materials ◽  
Optical Laser ◽  
Partial Depletion

Time-resolved investigations have begun a new era of chemistry and physics, enabling the monitoring in real time of the dynamics of chemical reactions and matter. Induced transient optical absorption is a basic ultrafast electronic effect, originated by a partial depletion of the valence band, that can be triggered by exposing insulators and semiconductors to sub-picosecond extreme-ultraviolet pulses. Besides its scientific and fundamental implications, this process is very important as it is routinely applied in free-electron laser (FEL) facilities to achieve the temporal superposition between FEL and optical laser pulses with tens of femtoseconds accuracy. Here, a set of methodologies developed at the FERMI facility based on ultrafast effects in condensed materials and employed to effectively determine the FEL/laser cross correlation are presented.

scholarly journals Time-resolved observation of transient precursor state of CO on Ru(0001) using carbon K-edge spectroscopy

2020 ◽  
Vol 22 (5) ◽  
pp. 2677-2684 ◽  
Author(s):  
Hsin-Yi Wang ◽  
Simon Schreck ◽  
Matthew Weston ◽  
Chang Liu ◽  
Hirohito Ogasawara ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Electronic Structure ◽  
Free Electron ◽  
Free Electron Laser ◽  
Transient Dynamics ◽  
Time Resolved ◽  
Precursor State ◽  
X Ray ◽  
Laser Pump ◽  
Optical Laser

The transient dynamics of carbon monoxide (CO) molecules on a Ru(0001) surface following femtosecond optical laser pump excitation has been studied by monitoring changes in the unoccupied electronic structure using an ultrafast X-ray free-electron laser (FEL) probe.

scholarly journals Free Electron Laser Measurement of Liquid Carbon Reflectivity in the Extreme Ultraviolet

Photonics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 35
Author(s):  
Sumana Raj ◽  
Shane Devlin ◽  
Riccardo Mincigrucci ◽  
Craig Schwartz ◽  
Emiliano Principi ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Lattice Dynamics ◽  
Extreme Ultraviolet ◽  
Wavelength Dependence ◽  
Optically Pumped ◽  
Liquid Carbon ◽  
Electronic Temperature ◽  
Time Resolved ◽  
Probing Depth

Ultrafast time-resolved extreme ultraviolet (EUV) reflectivity measurements of optically pumped amorphous carbon (a-C) have been performed with the FERMI free electron laser (FEL). This work extends the energy range used in previous reflectivity studies and adds polarization dependence. The EUV probe is known to be sensitive to lattice dynamics, since in this range the reflectivity is essentially unaffected by the photo-excited surface plasma. The exploitation of both s- and p-polarized EUV radiation permits variation of the penetration depth of the probe; a significant increase in the characteristic time is observed upon increasing the probing depth (1 vs. 5 ps) due to hydrodynamic expansion and consequent destruction of the excited region, implying that there is only a short window during which the probed region is in the isochoric regime. A weak wavelength dependence of the reflectivity is found, consistent with previous measurements and implying a maximum electronic temperature of 0.8 eV ± 0.4.

Generation and measurement of intense few-femtosecond superradiant extreme-ultraviolet free-electron laser pulses

2021 ◽  
Author(s):  
Najmeh S. Mirian ◽  
Michele Di Fraia ◽  
Simone Spampinati ◽  
Filippo Sottocorona ◽  
Enrico Allaria ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Laser Pulses

scholarly journals Measuring the frequency chirp of extreme-ultraviolet free-electron laser pulses by transient absorption spectroscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas Ding ◽  
Marc Rebholz ◽  
Lennart Aufleger ◽  
Maximilian Hartmann ◽  
Veit Stooß ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Transient Absorption ◽  
Extreme Ultraviolet ◽  
Ultrashort Pulses ◽  
Laser Pulses ◽  
Transient Absorption Spectroscopy ◽  
Energy Structure ◽  
Frequency Chirp

AbstractHigh-intensity ultrashort pulses at extreme ultraviolet (XUV) and x-ray photon energies, delivered by state-of-the-art free-electron lasers (FELs), are revolutionizing the field of ultrafast spectroscopy. For crossing the next frontiers of research, precise, reliable and practical photonic tools for the spectro-temporal characterization of the pulses are becoming steadily more important. Here, we experimentally demonstrate a technique for the direct measurement of the frequency chirp of extreme-ultraviolet free-electron laser pulses based on fundamental nonlinear optics. It is implemented in XUV-only pump-probe transient-absorption geometry and provides in-situ information on the time-energy structure of FEL pulses. Using a rate-equation model for the time-dependent absorbance changes of an ionized neon target, we show how the frequency chirp can be directly extracted and quantified from measured data. Since the method does not rely on an additional external field, we expect a widespread implementation at FELs benefiting multiple science fields by in-situ on-target measurement and optimization of FEL-pulse properties.

scholarly journals Two - Color Mid-Infrared Spectroscopy of Isoelectronic Centers in Silicon

2003 ◽  
Vol 770 ◽  
Author(s):  
N.Q. Vinh ◽  
T. Gregorkiewicz
Keyword(s):  
Excited States ◽  
Free Electron ◽  
Free Electron Laser ◽  
Materials Science ◽  
Time Resolved ◽  
Mid Infrared ◽  
Semiconductor Physics ◽  
Open Questions ◽  
Time Resolved Photoluminescence ◽  
Tunable Source

AbstractOne of the open questions in semiconductor physics is the origin of the small splittings of the excited states of bound excitons in silicon. A free electron laser as a tunable source of the mid-infrared radiation (MIR) can be used to investigate such splittings of the excited states of optical centers created by transition metal dopants in silicon. In the current study, the photoluminescence from silver and copper doped silicon is investigated by two color spectroscopy in the visible and the MIR. It is shown the PL due recombination of exciton bound to Ag and Cu is quenched upon application of the MIR beam. The time-resolved photoluminescence measurements and the quenching effects of these bands are presented. By scanning the wavelength of the free-electron laser ionization spectra of relevant traps involved in photoluminescence are obtained. The formation and dissociation of the bound excitons, and the small splittings of the effective-mass excited states are discussed. The applied experimental method allows correlation of DLTS data on trapping centers to specific channels of radiative recombination. It can be applied for spectroscopic analysis in materials science of semicondutors.

scholarly journals Time-resolved photoelectron imaging using a femtosecond UV laser and a VUV free-electron laser

2010 ◽  
Vol 81 (3) ◽  
Author(s):  
S. Y. Liu ◽  
Y. Ogi ◽  
T. Fuji ◽  
K. Nishizawa ◽  
T. Horio ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Uv Laser ◽  
Photoelectron Imaging ◽  
Time Resolved
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