Atoms In Optical Dipole Trap Research Articles

Increasing the trapping lifetime of lithium-7 atoms in optical dipole trap

We have developed far-off resonance single beam dipole trap for optically cooled lithium-7 atoms. In the present paper we discuss some preliminary results. In order to improve performance of the trap we optimized the trapping time and increased the atoms number. The lifetime was increased by improving the vacuum from ≈ 3 × 10−10 Torr to ≈ 10−11 Torr and preparing all the atoms in the selected atomic state (the lower ground state level). After vacuum improvement the single particle losses in the magneto-optical trap was reduced by 100 times and as the result the lifetime in the dipole trap reached 25 s.

Trapping of lithium atoms in a large hollow optical dipole trap

We describe the trapping of lithium atoms in an optical dipole trap about 1 mm in size, with a nearly rectangular potential. The trap has the shape of a cylinder with flat bases. The confinement region is bounded by thin walls produced by light with a frequency blue-detuned from an atomic transition (resonance) frequency by 19 GHz. Before trapping, the gas is collected and cooled in a magneto-optical trap whose centre nearly coincides with the centre of the dipole trap. After switching off the magneto-optical trap, we have photographed the atoms remaining in the dipole trap.

Ultracold collisions of mixed atoms in optical dipole trap loaded from a dark magneto-optical trap

We study the cold collisions of mixed atoms in an optical dipole trap (ODT), which are loaded from a dark magneto-optical trap (MOT). A comprehensive, phenomenological rate equation is presented to derive the ultracold homonuclear and heteronuclear collision rates in loading and holding procedures. Our results show that the cold atoms in the dark MOT can provide a much better stable, initial atomic sample than MOT. The dependence of the heteronuclear collision rate on the trap depth is attributed to the hyperfine-changing collision by the ODT laser with a broad linewidth. The processes of deriving the collision rate are also universal for other kinds of atoms or even molecules.