Schick, D.; Eckert, S.; Pontius, N.; Mitzner, R.; Föhlisch, A.; Holldack, K.; Sorgenfrei, F.: Versatile soft X-ray-optical cross-correlator for ultrafast applications. Structural Dynamics 3 (2016), p. 054304/1-8
10.1063/1.4964296
Open Accesn Version

Abstract:
We present an X-ray-optical cross-correlator for the soft (>150 eV) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%.