Atomic lighthouse effect

Abstract

We investigate the deflection of light by a cold atomic cloud when the light-matter interaction is locally tuned via the Zeeman effect using magnetic field gradients. This "lighthouse" effect is strongest in the single-scattering regime, where deviation of the incident field is largest. For optically dense samples, the deviation is reduced by collective effects, as the increase in linewidth leads to a decrease in magnetic field efficiency.

Decay dynamics in the coupled-dipole model

“…This is due to the destructive interference between the light emitted by the atoms in the two different half spaces. A similar idea, controlling the direction of the main diffraction lobe via the phase of the driven atoms, has been discussed in [60].…”

Collective scattering of light from disordered atomic clouds

“…Additionally to sub-and superradiance, this method was also capable to predict Mie resonances in cold atomic clouds 37 and brought new insights regarding on cooperative decay modes. 26 Actually, the first paper of this thesis (Section 3.1), the Atomic Lighthouse Effect, 38 is mainly based on this continuous approximation, and we show that the light scattered by an atomic cloud can be deviated by a gradient of magnetic field. Note that the CDM predicts a highly directional superradiant emission whose angular intensity distribution is concentrated in the forward direction.…”

“…In the dilute regime, this description can be approximated by a two level structure, which is, for example, the relevant regime of our following papers: the Atomic Lighthouse Effect, 38 the MirrorAssisted Coherent Backscattering 56 and the Optical Binding. However, a scalar theory is no longer a good approximation for Anderson Localization of Light 50 since it arises in the dense regime of disordered medium.…”