Towards GHz–THz cavity optomechanics in DBR-based semiconductor resonators

• Published in: Ultrasonics Vol. 56; pp. 80 - 89
• Main Authors: Lanzillotti-Kimura, N.D., Fainstein, A., Jusserand, B.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-02-2015; Elsevier
• Subjects: Alloys; Cavity optomechanics; Cavity resonators; Coefficients; Coherent phonon generation; Condensed Matter; Molecular structure; Phonons; Physics; Ps acoustics; Resonators; Semiconductor devices; Semiconductors; Time resolved; Cavity optomechanics; Coherent phonon generation; Semiconductor devices; Ps acoustics
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/j.ultras.2014.05.017

•Acoustic nanocavities are described that work in the GHz–THz range.•Optical microcavities are shown to enhance pump–probe signals.•DBR-based optical microcavites optimally confine both photons and phonons.•The photoelastic coupling in GaAs is strongly resonant with the direct gap.•DBR-based cavities are highly efficient optomechanic and optoelectronic resonators.
Resonators based on acoustic distributed Bragg reflectors (DBRs) were optimized to work in the GHz–THz regime, and grown by molecular beam epitaxy. We show that in structures made of GaAlAs alloys a simultaneous optimal confinement of light in the visible range and phonons in the tens of GHz range can be achieved. We report time resolved differential optical reflectivity experiments performed with fs–ps laser pulses. The experimental results are in excellent agreement with simulations based on standard transfer matrix methods. The resonant behavior of the photoelastic coefficient is discussed. The perfect optic-acoustic mode overlapping, added to a strongly enhanced coupling mechanism, implies that these DBR-based cavities could be the base of highly efficient optomechanical resonators.