Split-sideband spectroscopy in slowly modulated optomechanics

• Published in: New Journal of Physics
• Main Authors: E B Aranas, P Z G Fonseca, P F Barker, T S Monteiro
• Format: Article
• Language: English
• Published: IOP Publishing 2016-01-01
• Subjects: cavity optomechanics; levitated nanoparticles; quantum noise
• Online Access: https://doi.org/10.1088/1367-2630/18/11/113021

Optomechanical coupling between the motion of a mechanical oscillator and a cavity represents a new arena for experimental investigation of quantum effects on the mesoscopic and macroscopic scale. The motional sidebands of the output of a cavity offer ultra-sensitive probes of the dynamics. We introduce a scheme whereby these sidebands split asymmetrically and show how they may be used as experimental diagnostics and signatures of quantum noise limited dynamics. We show split-sidebands with controllable asymmetry occur by simultaneously modulating the light-mechanical coupling g and the mechanical frequency, ${\omega }_{{\rm{M}}}$ —slowly and out-of-phase. Such modulations are generic but already occur in optically trapped set-ups where the equilibrium point of the oscillator is varied cyclically. We analyse recently observed, but overlooked, experimental split-sideband asymmetries; although not yet in the quantum regime, the data suggests that split sideband structures are easily accessible to future experiments.