Mix ‘n’ probe with waves at FERMI


Transient grating pump-probe setup successfully tested at FERMI.

In the first days of July 2014, a team of scientists carried out a transient grating experiment on the DiProI beamline of FERMI, the FEL source operating at the Elettra research center in Trieste, Italy.

In this successful experiment, the scientists split a FEL pulse in two and recombine it at the sample with a finite crossing angle. “This generates a dynamic XUV grating”, says team leader Filippo Bencivenga, “which we then probe by an optical pulse coming from the seed laser of the FEL in a pump-probe, four-wave-mixing scheme. The coherent, non-linear, interaction of the three pulses originated a detectable coherent beam propagating along the phase matching direction.”

Such kind of non-linear XUV/soft x-ray wave-mixing experiments will be further developed at FERMI in a dedicated beamline (EIS-TIMER), also exploiting the unique capability of FERMI to radiate multi-colour seeded FEL pulses. A multi-colour transient grating approach would enable, for instance, to follow charge flows between constituent elements in molecules with femtosecond resolution, or to study energy transfer processes at the molecular scale.




Last Updated on Tuesday, 22 July 2014 12:52