Experimental setups for FEL-based four-wave mixing experiments at FERMI

Area of Science:

• Ultrafast spectroscopy
• Materials science
• Laser physics

Background:

• Advancements in free-electron laser (FEL) technology enable exploration of shorter wavelengths.
• Need for elemental selectivity and chemical state specificity in laser-matter interaction studies.
• Limitations of current table-top laser research at shorter wavelengths.

Purpose of the Study:

• To describe the design and construction of novel experimental facilities for four-wave-mixing (FWM) experiments.
• To introduce the EIS-TIMER beamline for studying ultrafast dynamics using FEL sources.
• To present preliminary results from the commissioning of the EIS-TIMER beamline.

Main Methods:

• Development of a compact setup (mini-TIMER) and a dedicated instrument (EIS-TIMER) for FWM experiments.
• Utilizing the transient grating approach with crossed FEL pulses to excite sample dynamics.
• Employing a time-delayed third FEL pulse for monitoring excited-state dynamics at fs-nm scales.

Main Results:

• Successful design and construction of the EIS-TIMER beamline as part of the Elastic and Inelastic Scattering (EIS) beamline.
• Demonstration of preliminary commissioning results for the EIS-TIMER.
• Development of novel experimental strategies for studying ultrafast dynamics.

Conclusions:

• The developed EIS-TIMER facility provides advanced capabilities for FEL-based FWM experiments.
• Future applications will include more sophisticated FWM studies using multiple and multi-color FEL pulses.
• These tools will significantly advance the study of matter dynamics at unprecedented time-length scales.