Search

Two-photon interference is a fundamental phenomenon in quantum mechanics and stands at the base of numerous experimental observations. Here another manifestation of this phenomenon is described, taking place at a Y junction. Specifically it is shown how the r^2+t^2 term which is behind previous observations of two-photon interference, may give rise to different states at a beam-splitter and different two-particle transmission coefficients at a Y junction. Different from previous descriptions of quantum transmission based on one-particle physics, the enhanced transmission described here is due to two-particle physics., Comment: Invited paper to a SPIE conference (San-Diego, 15-16 of August, 2012)

We investigate simultaneous optical trapping and optical detection of a single Rb atom near the surface of a toroidal microdisk. Light is coupled into two high-Q whispering-gallery modes of the disk which provide attractive and repulsive potentials, respectively, via their evanescent fields. The sum potential including van-der-Waals and Casimir-Polder surface forces exhibits a minimum at distances of the order of 100 nm from the disk surface. The back-action of an atom held in this trap on the light fields is sufficiently strong to provide a measurable effect. We discuss atom trapping and detection properties in dependence on a variety of system parameters.

We investigate the bound and evanescent fields of the optical whispering gallery modes which are supported by a toroid microcavity and which may be used for a wide range of applications. Results of simulations using finite-difference time domain solutions of Maxwell's equations are compared with semi-analytical solutions based on coupled mode theory. Key parameters such as resonance frequencies, transmittance characteristics, coupling efficiencies, and bending/scattering losses are analyzed as a function of experimental variables such as size, distance, and fabrication roughness. Finally, the feasibility of single-atom detection is discussed.