Dresden 2014 – scientific programme
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DF: Fachverband Dielektrische Festkörper
DF 9: Poster Session DF
DF 9.10: Poster
Tuesday, April 1, 2014, 18:30–20:00, P1
Selective preparation and detection of phonon polariton wavepackets by stimulated Raman scattering — •Jan-Etienne Pudell1, Jewgeni Goldshteyn2, Andre Bojahr1, Peter Gaal2, Daniel Schick1, and Matias Bargheer1,2 — 1Institut für Physik & Astronomie, Potsdam, Germany — 2Helmholtz Zentrum Berlin, Berlin, Germany
Wavevector-selective impulsive excitation of phonon-polaritons by a spectrally broad femtosecond transient gratings produces wavepackets propagating in opposite directions. The photons in spectrally narrow probe pulses are scattered from these elementary excitations in Lithium Niobate (LiNbO3). Both elastically and inelastically scattered photons are simultaneously detected in a spectrometer. The Stokes- and anti-Stokes shifted probe pulses uniquely determine the propagation direction of the detected polariton wavepacket component and correspond to creation and annihilation of phonon-polaritons, respectively. This experiment with spectrally broad pump and spectrally narrow probe pulses allows dissecting the four-wave-mixing process into two sequential stimulated Raman scattering events. Based on this analysis, we selectively prepare phonon-polariton wavepackets propagating only in one direction according to a spectrally assymmetric excitation by two light pulses.