XUV Split-and-Delay Lines: Performing XUV-XUV Pump-Probe Experiments at FLASH

Schematic layout of the BL2 split and delay unit

Split and delay unit at the PG2 beamline

At BL2, a grazing incidence split-and-delay unit (SDU), which was developed and built in a collaboration of HZB, Universität Münster, and DESY, was incorporated into the beamline to facilitate XUV-XUV pump-probe experiments. The device consists of eight mirrors under 6° grazing incidence which are positioned in a ultrahigh vacuum (UHV) chamber. A delay of -5 ps– +20 ps could be realized in this instrument with a 1 fs stability/reproducibility. The complete instrument could be shifted under vacuum to open a clear path through it, in case BL2 was to be used without the 'autocorrelator' (as we called the SDU).

M. Wöstmann et al., The XUV split-and-delay unit at beamline BL2 at FLASH, J. Phys. B: At. Mol. Opt. Phys. 46, 164005 (2013). Article


Sebastian Roling, Uni Münster and
Matthias Rollnik , Uni Münster

At the plane grating monochromator beamline PG2, a Mach-Zehnder type autocorrelator has been developed by the Universität Hamburg and implemented as a XUV split-and-delay line. The device is able to split the pulses and delay them up to ±5.1 ps with a stability in the 200 attosecond range. Both delay arms include an intensity monitor system to measure the beam splitting ratio online. A filter unit in the arms of the delay-line allows a choice of harmonics and thus two-colour XUV-XUV pump-probe experiments.

F. Sorgenfrei et al., The extreme ultraviolet split and femtosecond delay unit at the plane grating monochromator beamline PG2 at FLASH, Rev. Sci. Instrum. 81, 043107 (2010). Article


Günter Brenner
E-Mail: Günter Brenner
Phone: +49 (0)40 8998 (9)4527
Location: 28k / O2.022