Article abstract

Nature Physics 5, 909 - 914 (2009)
Published online: 11 October 2009 | doi:10.1038/nphys1425

Subject Category: Quantum physics

Near-field cavity optomechanics with nanomechanical oscillators

G. Anetsberger1, O. Arcizet1, Q. P. Unterreithmeier2, R. Rivière1, A. Schliesser1, E. M. Weig2, J. P. Kotthaus2 & T. J. Kippenberg1,3

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 ultrahigh-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-fmHz−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 platform, it can be readily extended to a diverse set of nanomechanical oscillators. In addition, the approach provides a route to experiments where radiation-pressure quantum backaction dominates at room temperature, enabling ponderomotive squeezing or quantum non-demolition measurements.

  1. Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany
  2. Fakultät für Physik and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität (LMU), Geschwister-Scholl-Platz 1, 80539 München, Germany
  3. Ecole Polytechnique Fédérale de Lausanne, EPFL, 1015 Lausanne, Switzerland

Correspondence to: T. J. Kippenberg1,3 e-mail: