An optically-levitated microsphere can be driven into rotation by coupling a rotating electric field to the permanent electric dipole moment, resulting in libration about the instantaneous direction of the electric field. This degree of freedom can be cooled by applying a phase modulation to the rotation of the electric field, effectively damping the motion. The degree of cooling is quantified by applying an impulse and observing the resulting exponential decay of the motion, as well as characterizing the thermally driven spectrum librational motion.
The universal law of gravitation has undergone stringent tests for many decades over a significant range of length scales, from atomic to planetary. Of particular interest is the short distance regime, where modifications to Newtonian gravity may arise from axion-like particles or extra dimensions. We have constructed an ultra-sensitive force sensor based on optically-levitated microspheres for the purpose of investigating non-Newtonian forces that couple to mass with a characteristic scale of 10µm. In this talk I will present the first investigation of the inverse-square law using an optically levitated test mass.
The universal law of gravitation has undergone stringent tests for many decades over a significant range of length scales, from atomic to planetary. Of particular interest is the short distance regime, where modifications to Newtonian gravity may arise from axion-like particles or extra dimensions. We have constructed an ultra-sensitive force sensor based on optically-levitated microspheres with a force sensitivity of $10^{-17}$ N/$sqrt{rm Hz}$ for the purpose of investigating non-Newtonian forces in the 1-100 $mu$m range. Microspheres interact with a variable-density attractor mass made by alternating silicon and gold segments with periodicity of 50 $mu$m. The attractor can be located as close as 10 $mu$m from a microsphere. I describe the characterization of this system, its sensitivity, and some preliminary results. Further technological developments to reduce background are expected to provide orders of magnitude improvement in the sensitivity, probing beyond current constraints on non-Newtonian interactions.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.