Optoacoustic cooling of traveling hypersound waves

TL;DR

This paper demonstrates optoacoustic cooling of hypersound waves in a fiber, achieving significant temperature reduction and opening pathways for quantum technology applications.

Contribution

It presents the first experimental realization of optoacoustic cooling of hypersound in a fiber using stimulated Brillouin scattering without sideband resolution.

Findings

Achieved a cooling rate of 219 K from room temperature.

Demonstrated cooling of a 7.38 GHz acoustic mode.

Showed potential for quantum technology applications.

Abstract

We experimentally demonstrate optoacoustic cooling via stimulated Brillouin-Mandelstam scattering in a 50 cm-long tapered photonic crystal fiber. For a 7.38 GHz acoustic mode, a cooling rate of 219 K from room temperature has been achieved. As anti-Stokes and Stokes Brillouin processes naturally break the symmetry of phonon cooling and heating, resolved sideband schemes are not necessary. The experiments pave the way to explore the classical to quantum transition for macroscopic objects and could enable new quantum technologies in terms of storage and repeater schemes.