Optoacoustic Active Cooling in Waveguides

Brillouin-Mandelstam scattering, the interaction of two photons mediated by an acoustic phonon, is one of the strongest third order nonlinearities in optical fibers. In contrast to optomechanical cavities, where Stokes and anti-Stokes processes interact with the same mechanical phonon, the acoustic phonons addressed in a backward Brillouin scattering process are different for Stokes and anti-Stokes processes. Therefore, in order to achieve phonon cooling, there is no need to work in the resolved sideband regime [1].