title: Communication: The formation of rarefaction waves in semiconductors after ultrashort excitation probed by grazing incidence ultrafast time-resolved x-ray diffraction.
abstract: We explore the InSb-semiconductor lattice dynamics after excitation of high density electron-hole plasma with an ultrashort and intense laser pulse. By using time resolved x-ray diffraction, a sub-mÅ and sub-ps resolution was achieved. Thus, a strain of 4% was measured in a 3 nm thin surface layer 2 ps after excitation. The lattice strain was observed for the first 5 ps as exponentially decaying, changing rapidly by time and by depth. The observed phenomena can only be understood assuming nonlinear time dependent laser absorption where the absorption depth decreases by a factor of twenty compared to linear absorption.
authors.forename: S
authors.initials: S
authors.lastname: Höfer
authors.forename: T
authors.initials: T
authors.lastname: Kämpfer
authors.forename: E
authors.initials: E
authors.lastname: Förster
authors.forename: T
authors.initials: T
authors.lastname: Stöhlker
authors.forename: I
authors.initials: I
authors.lastname: Uschmann