2015: Observation of generalized optomechanical coupling and cooling on cavity resonance

Scientists from the MSU Faculty of Physics jointly with their colleagues from Leibniz Universität (Hannover) and Max-Planck Institut für Gravitationsphysik (Hannover) demonstrated for the first time the generalized (that is, dispersive and dissipative) optomechanical coupling.

Optomechanical coupling between a light field and the motion of a cavity mirror via radiation pressure plays an important role for the exploration of macroscopic quantum physics and for very high precision measurement of mechanical displacements and forces, including the detection of gravitational waves (GWs). It has been used to cool mechanical oscillators into their quantum ground states and has been considered to boost the sensitivity of GW detectors, e.g. via the optical spring effect.

In the work by a joint group of scientists from the Leibniz Universität (Hannover), the Max-Planck Institut für Gravitationsphysik (Hannover), and the Physics Faculty of Moscow State University, the generalized (that is, dispersive and dissipative) optomechanical coupling with a silicon nitride membrane in a cavity-enhanced Michelson-type interferometer was demonstrated. Strong (down to 110 mK) optical cooling based on dissipative coupling was achieved for the first time. These results will allow for new experimental regimes in macroscopic quantum physics and GW detection.

The results of this work have been published in the paper: A.Sawadsky, H.Kaufer, R.M. Nia, S.P.Tarabrin, F.Ya.Khalili, K.Hammerer, and R.Schnabel, “Observation of Generalized Optomechanical Coupling and Cooling on Cavity Resonance”, Phys. Rev. Letters 114, 043601 (2015).