Mini-TIMER: four wave mixing with FEL transient gratings

Extreme ultraviolet four wave mixing have been demonstrated at the DiProI beamline producing a transient grating with 70 fs FEL pulses, split into two halves and recombined on the sample with a known delay, and probing it with a 100 fs ultraviolet pulse to produce a fourth signal beam.

Bencivenga et al., Nature 520, 205 (2015).

Four wave mixing experimental setup

A miniaturized delay line composed of three 70 mm long carbon-coated mirrors, with position and pointing remotely controlled with piezo-motor actuators, fits within the DiProI end station. Each beam can be synchronized with the ultraviolet pump monitoring the FEL-induced ultrafast reflectivity change of a Si3N4 target.

The time dependence of the transient grating signal is featured by a clear peak, centered at zero time delay and with a FWHM ≈ 150 fs, and modulations likely due to vibrations (Raman and Brillouin modes).

An appreciable signal (> 104 photons/shot) was observed in the whole probed time delay range (0-100 ps).

Retrieve article

Four-wave mixing experiments with extreme ultraviolet transient gratings.

F. Bencivenga, R. Cucini, F. Capotondi, A. Battistoni, R. Mincigrucci, E. Giangrisostomi, A. Gessini, M. Manfredda, I.P. Nikolov, E. Pedersoli, E. Principi, C. Svetina, P. Parisse, F. Casolari, M.B. Danailov, M. Kiskinova, C. Masciovecchio.

Nature 520, 205 (2015).

DOI: doi:10.1038/nature14341


Last Updated on Monday, 21 December 2015 10:57