Optomechanical properties of GaAs/AlAs micropillar resonators operating in the 18 GHz range

TL;DR

This paper numerically investigates GaAs/AlAs micropillar resonators operating around 18 GHz, revealing their strong optomechanical coupling and the influence of boundary conditions and geometry on their properties.

Contribution

It provides new insights into the optomechanical behavior of GaAs/AlAs micropillars, highlighting the impact of boundary conditions and geometry on their performance.

Findings

Mechanical quality factor depends strongly on micropillar radius.

Optomechanical coupling constants reach ultra-large values (~10^6 rad/s).

Poisson's ratio and boundary conditions significantly affect confinement features.

Abstract

Recent experiments demonstrated that GaAs-AlAs based micropillar cavities are promising systems for quantum optomechanics, allowing the simultaneous three-dimensional confinement of near-infrared photons and acoustic phonons in the 18-100 GHz range. Here, we investigate through numerical simulations the optomechanical properties of this new platform. We evidence how the Poisson's ratio and semiconductor-vacuum boundary conditions lead to very distinct features in the mechanical and optical three dimensional confinement. We find a strong dependence of the mechanical quality factor and strain distribution on the micropillar radius, in great contrast to what is predicted and observed in the optical domain. The derived optomechanical coupling constants g_0 reach ultra-large values in the 10^6 rad/s range.