Laser-Excited Acoustical Phonons Probed By Ultrashort Pulses From A Laser-Driven X-Ray Diode

We demonstrate that an ultrashort-pulse laser-driven x-ray diode can be used for time-resolved experiments on a picosecond timescale. Hence, acoustical phonons in germanium are observed after ultrashort laser-excitation and the results are compared with calculations according to a microphysical model. We also show the advantages of this kind of picosecond x-ray source compared to other sources on the basis of its properties. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3577605]