@inproceedings{SidersCavalleriTothetal., author = {Siders, C. W. and Cavalleri, Andrea and T{\´o}th, Csaba and Wilson, K. R. and Squier, Jeff A. and Barty, C. P. J. and Kammler, Martin and Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D.}, title = {Femtosecond X-ray diffraction of short-pulse irradiated semiconductors}, series = {Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges, 24-24 May 2002, Long Beach, CA, USA}, booktitle = {Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges, 24-24 May 2002, Long Beach, CA, USA}, publisher = {IEEE}, doi = {10.1109/CLEO.2002.1033997}, pages = {297 -- 298}, abstract = {Summary form only given, as follow. Ultrafast optical-pump, X-ray diffraction probe experiments are providing new ways to study transient processes including the direct observation of the atomic motion by which many solid-state processes and chemical and biochemical reactions take place. Current table-top-terawatt femtosecond laser systems provide an attractive source of few-hundred femtosecond duration bursts of angstrom-scale X-ray radiation with fluxes comparable to standard rotating anode sources. Their compact size enables time resolved structural dynamics to be studied in the small laboratory with temporal resolution better than typical molecular vibrational periods. Ultrafast structural dynamics in crystalline samples are readily studied with such systems and experiments to be discussed in this talk include ultrafast non-thermal solid-to-liquid transition in thin single-crystal Ge-111 films grown on Si-111 substrates; ultrafast non-thermal solid-to-solid transitions in bulk vanadium dioxide from a low temperature insulating phase to a high temperature metallic phase; and harmonic and anharmonic coherent acoustic dynamics in layered Ge-111/Si-111 and bulk GaAs-111 samples. Future improvements in high-average power short-pulse lasers will enable the study of a wider class of materials such as amorphous solids or liquid-phase dynamics of simple molecules, while proposed 4th generation light sources based upon single-pass X-ray free-electron lasers will permit singleshot structural determination of complex biomolecules.}, language = {en} } @article{SokolowskiTintenHornvonHoegenvonderLindeetal., author = {Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and Leitner, D. M. and T{\´o}th, Csaba and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R. and Kammler, Martin}, title = {Transient lattice dynamics in fs-laser-excited semiconductors probed by ultrafast X-ray diffraction}, series = {Journal de Physique IV}, volume = {11}, journal = {Journal de Physique IV}, number = {Pr2}, publisher = {EDP}, doi = {10.1051/jp4:2001290}, pages = {473 -- 477}, abstract = {A study of lattice dynamics in fs-laser-excited crystalline bulk Ge and Ge/Si-heterostructures, using time-resolved x-ray diffraction, was presented. Fast energy transport deep into the bulk of the material, coherent acoustic phonon dynamics, lattice anharmonicity, and vibrational transport across a buried interfaces were observed. Graphs showing time-dependent shifts of the centroid of the measured rocking curves in the Ge-overlayer and in the Si-substrate for different fluences, were presented.}, language = {en} } @article{SokolowskiTintenCavalleriSidersetal., author = {Sokolowski-Tinten, Klaus and Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and Leitner, D. M. and T{\´o}th, Csaba and Kammler, Martin and Horn-von Hoegen, Michael and von der Linde, D. and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R.}, title = {Time-resolved x-ray diffraction study of ultrafast acoustic phonon dynamics in Ge/Si-heterostructures}, series = {Chemical Physics}, volume = {66}, journal = {Chemical Physics}, publisher = {Springer}, doi = {10.1007/978-3-642-56546-5_81}, pages = {281 -- 283}, abstract = {Using time-resolved x-ray diffraction the ultafast strain dynamics in fs-laserexcited Ge/Si-heterostructures has been studied. A fluence dependent, anharmonic damping of the impulsively generated acoustic phonons and vibrational transport across the buried Ge/Si-interface are observed.}, language = {en} } @article{CavalleriSidersBrownetal., author = {Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and Leitner, D. M. and T{\´o}th, Csaba and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R. and Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D. and Kammler, Martin}, title = {Anharmonic lattice dynamics in germanium measured with ultrafast x-ray diffraction}, series = {Physical review letters}, volume = {85}, journal = {Physical review letters}, number = {3}, publisher = {APS}, doi = {10.1103/PhysRevLett.85.586}, pages = {586 -- 589}, abstract = {Damping of impulsively generated coherent acoustic oscillations in a femtosecond laser-heated thin germanium film is measured as a function of fluence by means of ultrafast x-ray diffraction. By simultaneously measuring picosecond strain dynamics in the film and in the unexcited silicon substrate, we separate anharmonic damping from acoustic transmission through the buried interface. The measured damping rate and its dependence on the calculated temperature of the thermal bath is consistent with estimated four-body, elastic dephasing times (T2) for 7-GHz longitudinal acoustic phonons in germanium.}, language = {en} } @article{SokolowskiTintenHornvonHoegenvonderLindeetal., author = {Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and T{\´o}th, Csaba and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R. and Kammler, Martin}, title = {Time-resolved x-ray diffraction study of ultrafast acoustic phonon dynamics in Ge/Si-heterostructures}, series = {International Conference on Ultrafast Phenomena , 9 July 2000, Charleston}, journal = {International Conference on Ultrafast Phenomena , 9 July 2000, Charleston}, publisher = {Optica}, abstract = {Using time-resolved x-ray diffraction the ultafast strain dynamics in fs-laserexcited Ge/Si-heterostructures has been studied. A fluence dependent, anharmonic damping of the impulsively generated acoustic phonons and vibrational transport across the buried Ge/Si-interface are observed.}, language = {en} }