Radial Confinement of Light in an Ultracold Anisotropic Medium

We demonstrate radial confinement and waveguiding of light in an ultracold anisotropic gas. The waveguiding medium is a laser cooled ensemble of rubidium atoms confined in a trap of large aspect ratio. A recoil induced resonance (RIR) is used to create strong dispersion and large gain in this ensemble. The combination of the anisotropic trap and the RIR give rise to a spatially varying group refractive index resulting in a slow-light optical waveguide. Waveguided pulses of light experience strong gain (∼50), low group velocities (c∼1500  m/s), and long group delays (δ∼7  μs) due to the enhanced path length.