Gabriel Price

Direct Observation of Sub-Poissonian Number Statistics in a Degenerate Bose Gas

We report the direct observation of sub-Poissonian number fluctuation for a degenerate Bose gas confined in an optical trap. Reduction of number fluctuations below the Poissonian limit is observed for average numbers that range from 300 to 60 atoms.

Single-photon atomic cooling

We report the cooling of an atomic ensemble with light, where each atom scatters only a single photon on average. This is a general method that does not require a cycling transition and can be applied to atoms or molecules that are magnetically trapped. We discuss the application of this new approach to the cooling of hydrogenic atoms for the purpose of precision spectroscopy and fundamental tests.

Distributed feedback micro-laser array: helixed liquid crystals embedded in holographically sculptured polymeric microcavities

We report a detailed physical characterization of a novel array of organic distributed feedback microcavity lasers possessing a high ratio between the quality factor Q of the resonant cavity and its volume V. The optical microcavity was obtained by confining self-organized mesophases doped with fluorescent guest molecules into holographically patterned polymeric microchannels. The liquid crystal microchannels act as mirror-less cavity lasers, where the emitted laser light propagates along the liquid crystal helical axis behaving as Bragg resonator. This miniaturization process allows us to obtain a micro-laser array possessing an ultralow lasing threshold (25nJ/pulse) while having directional control on the lasing emission, a fine wavelength tunability and the control over the emission intensity.

Single-photon cooling at the limit of trap dynamics: Maxwell's demon near maximum efficiency

We demonstrate a general and efficient informational cooling technique for atoms that is an experimental realization of a one-dimensional Maxwells demon. The technique transfers atoms from a magnetic trap into an optical trap via a single spontaneous Raman transition that is discriminatively driven near each atoms classical turning point. In this way, nearly all of the atomic ensembles kinetic energy in one dimension is removed. We develop a simple analytical model to predict the efficiency of transfer between the traps and provide evidence that the performance is limited only by particle dynamics in the magnetic trap. Transfer efficiencies up to 2.2% are reported. We show that efficiency can be traded for phase-space compression, and we report compression up to a factor of 350. Our results represent a 15-fold improvement over our previous demonstration of the cooling technique.