Optoelectronic forces with quantum wells for cavity optomechanics in GaAs/AlAs semiconductor microcavities

VILLAFAÑE, V.; SESIN, P.; SOUBELET, P.; ANGUIANO, S.; BRUCHHAUSEN, A. E.; ROZAS, G.; CARBONELL, C. GOMEZ; LEMAÎTRE, A.; FAINSTEIN, A.

Physical Review B

APS

Año: 2018 vol. 97

2469-9950

Radiation pressure, electrostriction, and photothermal forces have been investigated to evidence backaction,nonlinearities, and quantum phenomena in cavity optomechanics. We show here through a detailed study of therelative intensity of the cavity mechanical modes observed when exciting with pulsed lasers close to the GaAsoptical gap that optoelectronic forces involving real carrier excitation and deformation potential interaction arethe strongest mechanism of light-to-sound transduction in semiconductor GaAs/AlAs distributed Bragg reflectoroptomechanical resonators. We demonstrate that the ultrafast spatial redistribution of the photoexcited carriers inmicrocavities with massive GaAs spacers leads to an enhanced coupling to the fundamental 20-GHz verticallypolarized mechanical breathing mode. The carrier diffusion along the growth axis of the device can be enhancedby increasing the laser power, or limited by embedding GaAs quantum wells in the cavity spacer, a strategy usedhere to prove and engineer the optoelectronic forces in phonon generation with real carriers. The wavelengthdependence of the observed phenomena provide further proof of the role of optoelectronic forces. The opticalforces associated with the different intervening mechanisms and their relevance for dynamical backaction inoptomechanics are evaluated using finite-element methods. The results presented open the path to the study ofhitherto seldom investigated dynamical backaction in optomechanical solid-state resonators in the presence ofoptoelectronic forces.