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arXiv · 0904.4051

Near-field cavity optomechanics with nanomechanical oscillators

G. Anetsberger·O. Arcizet·Q. P. Unterreithmeier·R. Rivière·A. Schliesser·E. M. Weig·J. P. Kotthaus·T. J. Kippenberg
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Abstract

Cavity-enhanced radiation pressure coupling between optical and mechanical degrees of freedom allows quantum-limited position measurements and gives rise to dynamical backaction enabling amplification and cooling of mechanical motion. Here we demonstrate purely dispersive coupling of high Q nanomechanical oscillators to an ultra-high finesse optical microresonator via its evanescent field, extending cavity optomechanics to nanomechanical oscillators. Dynamical backaction mediated by the optical dipole force is observed, leading to laser-like coherent nanomechanical oscillations solely due to radiation pressure. Moreover, sub-fm/Hz^(1/2) displacement sensitivity is achieved, with a measurement imprecision equal to the standard quantum limit (SQL), which coincides with the nanomechanical oscillator's zero-point fluctuations. The achievement of an imprecision at the SQL and radiation-pressure dynamical backaction for nanomechanical oscillators may have implications not only for detecting quantum phenomena in mechanical systems, but also for a variety of other precision experiments. Owing to the flexibility of the near-field coupling approach, it can be readily extended to a diverse set of nanomechanical oscillators and particularly provides a route to experiments where radiation pressure quantum backaction dominates at room temperature, enabling ponderomotive squeezing or QND measurements.

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G. Anetsberger, O. Arcizet, Q. P. Unterreithmeier, R. Rivière, A. Schliesser, E. M. Weig, J. P. Kotthaus, T. J. Kippenberg. 2009-09-07. Near-field cavity optomechanics with nanomechanical oscillators. https://doi.org/10.1038/nphys1425

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