Coherent generation of acoustic phonons in an optical microcavity

Abstract

Coherent acoustic phonons confined in a nanocavity are generated in an optical microcavity. The confinement of the femtosecond light pulse in the optical resonator amplifies both processes, generation and detection of the acoustic phonons. In addition, due to the standing wave character of the photon field, phonons of wavevector q = 0 and q = 2k (k is the light wavenumber) contribute to both the generation and detection in time resolved reflectivity measurements, further optimizing the pump and probe experiments. Time resolved differential reflectivity experiments are reported as a function of laser energy. The optical cavity resonance is apparent in the amplitude and spectral features of the Fourier transformed signals. © 2007 IOP Publishing Ltd.