Selective optical generation of coherent acoustic nanocavity modes

WINTER MFP, ROZAS G, FAINSTEIN A, ET AL.

PHYSICAL REVIEW LETTERS

Año: 2007 vol. 98 p. 265501 - 265501

0031-9007

Femtosecond pump-probe experiments on a Ga0.85In0.15As nanocavity enclosed by two Ga0.85In0.15As/AlAs 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.