TY  - JOUR
A1  - Gaal, P.
A1  - Schick, Daniel
A1  - Herzog, Marc
A1  - Bojahr, Andre
A1  - Shayduk, Roman
A1  - Goldshteyn, J.
A1  - Navirian, Hengameh A.
A1  - Leitenberger, Wolfram
A1  - Vrejoiu, Ionela
A1  - Khakhulin, D.
A1  - Wulff, M.
A1  - Bargheer, Matias
T1  - Time-domain sampling of x-ray pulses using an ultrafast sample response
JF  - Applied physics letters
N2  - We employ the ultrafast response of a 15.4 nm thin SrRuO3 layer grown epitaxially on a SrTiO3 substrate to perform time-domain sampling of an x-ray pulse emitted from a synchrotron storage ring. Excitation of the sample with an ultrashort laser pulse triggers coherent expansion and compression waves in the thin layer, which turn the diffraction efficiency on and off at a fixed Bragg angle during 5 ps. This is significantly shorter than the duration of the synchrotron x-ray pulse of 100 ps. Cross-correlation measurements of the ultrafast sample response and the synchrotron x-ray pulse allow to reconstruct the x-ray pulse shape.
Y1  - 2012
U6  - https://doi.org/10.1063/1.4769828
SN  - 0003-6951
VL  - 101
IS  - 24
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Navirian, Hengameh A.
A1  - Herzog, Marc
A1  - Goldshteyn, J.
A1  - Leitenberger, Wolfram
A1  - Vrejoiu, Ionella
A1  - Khakhulin, D.
A1  - Wulff, M.
A1  - Shayduk, Roman
A1  - Gaal, P.
A1  - Bargheer, Matias
T1  - Shortening x-ray pulses for pump-probe experiments at synchrotrons
JF  - Journal of applied physics
N2  - We implemented an experimental scheme for ultrafast x-ray diffraction at storage rings based on a laser-driven Bragg-switch that shortens the x-ray pulses emitted from an undulator. The increased time-resolution is demonstrated by observing changes of intensity, position and width of the diffraction peaks of a La(0.7)Sr(0.3)MnO(3)/SrTiO(3) superlattice sample after optical excitation, i.e., by quantitatively measuring the propagation of an expansion wave through the sample. These experimental transients with timescales of 35 to 60 ps evidence a reduction of the x-ray pulse duration by a factor of two.
Y1  - 2011
U6  - https://doi.org/10.1063/1.3601057
SN  - 0021-8979
VL  - 109
IS  - 12
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Herzog, Marc
A1  - Bojahr, Andre
A1  - Goldshteyn, J.
A1  - Leitenberger, Wolfram
A1  - Vrejoiu, I.
A1  - Khakhulin, D.
A1  - Wulff, M.
A1  - Shayduk, Roman
A1  - Gaal, P.
A1  - Bargheer, Matias
T1  - Detecting optically synthesized quasi-monochromatic sub-terahertz phonon wavepackets by ultrafast x-ray diffraction
JF  - Applied physics letters
N2  - We excite an epitaxial SrRuO3 thin film transducer by a pulse train of ultrashort laser pulses, launching coherent sound waves into the underlying SrTiO3 substrate. Synchrotron-based x-ray diffraction (XRD) data exhibiting separated sidebands to the substrate peak evidence the excitation of a quasi-monochromatic phonon wavepacket with sub-THz central frequency. The frequency and bandwidth of this sound pulse can be controlled by the optical pulse train. We compare the experimental data to combined lattice dynamics and dynamical XRD simulations to verify the coherent phonon dynamics. In addition, we observe a lifetime of 130 ps of such sub-THz phonons in accordance with the theory.
KW  - acoustic waves
KW  - epitaxial layers
KW  - phonon dispersion relations
KW  - terahertz waves
KW  - thin film devices
KW  - X-ray diffraction
Y1  - 2012
U6  - https://doi.org/10.1063/1.3688492
SN  - 0003-6951
VL  - 100
IS  - 9
PB  - American Institute of Physics
CY  - Melville
ER  -