6 research outputs found
Dynamical Backaction in an Ultrahigh-Finesse Fiber-Based Microcavity
The use of low-dimensional objects in the field of cavity optomechanics is limited by their low scattering cross section compared with the size of the optical cavity mode. Fiber-based Fabry-Perot microcavities can feature tiny mode cross sections and still maintain a high finesse, boosting the light-matter interaction and thus enabling the sensitive detection of the displacement of minute objects. Here we present such an ultrasensitive microcavity setup with the highest finesse reported so far in loaded fiber cavities, F=195000. We are able to position-tune the static optomechanical coupling to a silicon nitride membrane stripe, reaching frequency pull parameters of up to G/2Ï€=1GHz/nm. We also demonstrate radiation pressure backaction in the regime of an ultrahigh finesse up to F=165000
Fluctuating nanomechanical systems in a high finesse optical microcavity
Confining a laser field between two high reflectivity mirrors of a
high-finesse cavity can increase the probability of a given cavity photon to be
scattered by an atom traversing the confined photon mode. This enhanced
coupling between light and atoms is successfully employed in cavity quantum
electrodynamics experiments and led to a very prolific research in quantum
optics. The idea of extending such experiments to sub-wavelength sized
nanomechanical systems has been recently proposed in the context of optical
cavity cooling. Here we present an experiment involving a single nanorod
consisting of about 10^9 atoms precisely positioned to plunge into the confined
mode of a miniature high finesse Fabry-Perot cavity. We show that the optical
transmission of the cavity is affected not only by the static position of the
nanorod but also by its vibrational fluctuation. While an imprint of the
vibration dynamics is directly detected in the optical transmission,
back-action of the light field is also anticipated to quench the nanorod
Brownian motion. This experiment shows the first step towards optical cavity
controlled dynamics of mechanical nanostructures and opens up new perspectives
for sensing and manipulation of optomechanical nanosystems.Comment: 16 pages, including 4 figure
Assessing the Impact of Risk Contagion on Value-at-Risk and the Alternative Application of a Bayesian Factor Based Approach.
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Optical instability and self-pulsing in silicon nitride whispering gallery resonators
We report time domain observations of optical instability in high Q silicon nitride whispering gallery disk resonators. At low laser power the transmitted optical power through the disk looks chaotic. At higher power, the optical output settles into a stable self-pulsing regime with periodicity ranging from hundreds of milliseconds to hundreds of seconds. This phenomenon is explained by the interplay between a fast thermo-optic nonlinearity within the disk and a slow thermo-mechanic nonlinearity of the structure. A model for this interplay is developed which provides good agreement with experimental data and points out routes to control this instability
Media 1: Optical instability and self-pulsing in silicon nitride whispering gallery resonators
Originally published in Optics Express on 17 December 2012 (oe-20-27-29076