Gorodetksy, M. L.Schliesser, A.Anetsberger, G.Deleglise, S.Kippenberg, T. J.2011-12-162011-12-162011-12-16201010.1364/OE.18.023236https://infoscience.epfl.ch/handle/20.500.14299/75039WOS:000283560400065The strength of optomechanical interactions in a cavity optomechanical system can be quantified by a vacuum coupling rate g(0) analogous to cavity quantum electrodynamics. This single figure of merit removes the ambiguity in the frequently quoted coupling parameter defining the frequency shift for a given mechanical displacement, and the effective mass of the mechanical mode. Here we demonstrate and verify a straightforward experimental technique to derive the vacuum optomechanical coupling rate. It only requires applying a known frequency modulation of the employed electromagnetic probe field and knowledge of the mechanical oscillator's occupation. The method is experimentally verified for a micromechanical mode in a toroidal whispering-gallery-resonator and a nanomechanical oscillator coupled to a toroidal cavity via its near field. (C) 2010 Optical Society of AmericaFabry-Perot-InterferometerRadiation-PressureMicromechanical OscillatorCavity OptomechanicsModesStabilizationMicrospheresSensitivityResonatorMotiontext::journal::journal article::research article