Abstract

Researchers can optically cool solids at the scale of individual atoms with fluorescence techniques, and the vibrations of entire devices with optomechanical techniques. Our team developed a cooling method for the intermediate regime between atomic and device scale. This technique allows us to cool collective atomic motion in the form of acoustical waves by inverting the energy flow in the Brillouin scattering light-sound interaction. In such interactions, incident photons are scattered to redder (Stokes) or bluer (anti-Stokes) frequencies, while heating or cooling the medium as required by energy conservation. It was thought that this coolingheating balance is always tilted towards heating as governed by Planck distribution, which is indeed true in bulk media where all photons are almost equally transmitted.

© 2012 Optical Society of America