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2007
Conference Paper
Titel
Coherent acoustic phonons in phonon cavities investigated by asynchronous optical sampling
Alternative
Kohärente akustische Phononen in Phononenaktivitäten untersucht mittels asynchronem optischen Abtasten
Abstract
Using a recently introduced measurement technique, called asynchronous optical sampling (ASOPS), we have investigated the dynamics of coherent acoustic phonons in a semiconductor heterostructure composed of a GaAs film between two GaAs/AlAs superlattices, serving as a cavity for acoustic phonons. Measurements were performed at liquid helium temperatures. The possibility to perform two-color pump-probe spectroscopy allowed us to tune the probe pulse energy to the cavity band gap, while sweeping the pump pulse energy over the superlattice resonance. The large measurement window of 1 ns in combination with a resolution of about 150 fs made a detailed analysis of the observed phonon dynamics possible. We observed a long lived oscillation in the gap of the phonon dispersion at 466 GHz, which we attribute to a cavity mode.
Author(s)