76 research outputs found
Upper Bound Imposed upon Responsivity of Optical Modulators
We study theoretically the responsivity of optical modulators. For the case
of linear response we find using perturbation theory an upper bound imposed
upon the responsivity. For the case of two mode modulator we find a lower bound
imposed upon the optical path required for achieving full modulation when the
maximum birefringence strength is given
Sensing Dispersive and Dissipative Forces by an Optomechanical Cavity
We experimentally study an optomechanical cavity that is formed between a
mechanical resonator, which serves as a movable mirror, and a stationary
on-fiber dielectric mirror. A significant change in the behavior of the system
is observed when the distance between the fiber's tip and the mechanical
resonator is made smaller than about 1 micrometer. The observed effects are
attributed to the combined influence of Casimir force, Coulomb interaction due
to trapped charges, and optomechanical coupling. The comparison between
experimental results and theory yields a partial agreement
Damping in a Superconducting Mechanical Resonator
We study a mechanical resonator made of aluminum near the normal to super
conductivity phase transition. A sharp drop in the rate of mechanical damping
is observed below the critical temperature. The experimental results are
compared with predictions based on the Bardeen Cooper Schrieffer theory of
superconductivity and a fair agreement is obtained
Decoherence and Recoherence in a Vibrating RF SQUID
We study an RF SQUID, in which a section of the loop is a freely suspended
beam that is allowed to oscillate mechanically. The coupling between the RF
SQUID and the mechanical resonator originates from the dependence of the total
magnetic flux threading the loop on the displacement of the resonator. Motion
of the latter affects the visibility of Rabi oscillations between the two
lowest energy states of the RF SQUID. We address the feasibility of
experimental observation of decoherence and recoherence, namely decay and rise
of the visibility, in such a system.Comment: 9 pages, 2 figure
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