Abstract
Femtosecond pump-probe experiments on a nanocavity enclosed by two phonon Bragg mirrors reveal selective generation of terahertz confined acoustic modes and regular folded phonons. Selective generation of the confined modes alone is achievable for laser excitation at certain energies below the mirror absorption edges, corresponding to electronic transitions within the cavity layer only. Calculations based on the photoelastic effect explain the experimental results. Decay times of cavity and regular modes evidence longer decay times and anharmonic effects for the cavity mode.
- Received 30 January 2007
DOI:https://doi.org/10.1103/PhysRevLett.98.265501
©2007 American Physical Society