Gaal, P.; Schick, D.; Herzog, M.; Bojahr, A.; Shayduk, R.; Goldshteyn, J.; Leitenberger, W.; Vrejoiu, I.; Khakhulin, D.; Wulff, M.; Bargheer, M.: Ultrafast switching of hard X-rays. Journal of Synchrotron Radiation 21 (2014), p. 380-385

A new concept for shortening hard X-ray pulses emitted from a third-generation synchrotron source down to few picoseconds is presented. The device, called the PicoSwitch, exploits the dynamics of coherent acoustic phonons in a photoexcited thin film. A characterization of the structure demonstrates switching times of < 5 ps and a peak reflectivity of ~10^-3. The device is tested in a real synchrotron-based pump–probe experiment and reveals features of coherent phonon propagation in a second thin film sample, thus demonstrating the potential to significantly improve the temporal resolution at existing synchrotron facilities.