Nonlinear beam shaping in an anisotropic magneto-optical trap

Rudy Romain, Philippe Verkerk, Daniel Hennequin

Joel A. Greenberg, Marcos Oriá, Andrew M. C. Dawes +1 more

We report on a simple anisotropic magneto-optical trap for neutral atoms that produces a large sample of cold atoms confined in a cylindrically-shaped volume with a high aspect ratio (100:1). Due to the large number of trapped atoms, the laser beams that propagate along the optically thick axis of the trap to cool the atoms are substantially attenuated. We demonstrate that the resulting intensity imbalance produces a net force that spatially localizes the atoms. This limits both the trap length and the total number of trapped atoms. Rotating the cooling beams by a small angle relative to the trap axis avoids the problem of attenuation, and atoms can be trapped throughout the entire available trapping volume. Numerical and experimental results are reported that demonstrate the effects of absorption in an anisotropic trap, and a steady-state, line-center optical path length of 55 is measured for a probe beam propagating along the length of the trap.

Chasen S Himeda

G. Dudle, N Sagna, P. Berthoud +1 more

An anisotropic magneto-optical trap is studied as the potential source of a continuous beam of laser-cooled atoms. Capture efficiency and cloud temperature are measured experimentally and found to be lower than in an isotropic situation with the same cooling parameters. Intensity imbalance and static magnetic field are investigated as possible extraction mechanisms. While only small drift velocities are induced by means of intensity imbalance, velocities of tens of are observed with a static magnetic field; the shape of the observed two-peaked velocity distributions is related to the average depth of local light-shift-induced potential wells.

Sahar Behroozinia, Jiazhen Li, Elaheh Karooby +1 more

We design a multi-functional metasurface that simultaneously performs polarization conversion, beam expansion, and flat-top intensity shaping for compact magneto-optical trap (MOT) systems. The metasurface enables an alignment-free optical interface that can support robust MOT operation.

J. W. R. Tabosa, S. S. Vianna, Clayton Augusto Benevides