Orateur
Dr
Riccardo Faoro
(Joint Quantum Centre Durham-Newcastle, Durham University Durham, UK)
Description
Cooperative quantum optics has been one of the main research topics to emerge in the field of cold Rydberg gases. The first observations of optical nonlinearity at the single-photon level, and more recent demonstrations of single-photon transistors use a resonant two-photon excitation scheme. A key figure of merit is the optical depth per blockade sphere, which must be very high to ensure that all unwanted photons are scattered. Using a cold ($\sim$ 10 $\mu$K), dense (up to $\sim$ $10^{12}$ cm$^{-3}$) gas of strontium atoms we show that in this regime, a significant Rydberg population can be created by photons that are multiply scattered before leaving the cloud. The re-scattered field is density-dependent and has quite different spectral properties from the incident laser light. A careful analysis reveals that multiple scattering co-exists with signatures of the Rydberg blockade in this strongly dissipative regime. Our technique also provides a probe of the spectral distribution of the re-scattered light within the cloud, which may be qualitatively different from that of the transmitted light.
Auteur principal
Dr
Riccardo Faoro
(Joint Quantum Centre Durham-Newcastle, Durham University Durham, UK)
