A continuous source of magnetically guided dark state atoms
Abstract
We have created a steady flow (10^6/s) of ultracold 87 Rb atoms in the dark F=1, mF= -1 ground state. The atoms are first captured from the background vapor in a horizontal magneto-optical waveguide (MOW) using the F=2 to 3 transition. The magnetic field gradient in the trapped dimensions is 100 G/cm, about ten times the gradient of a standard magneto-optical trap. As the atoms move along the guide with an adjustable initial velocity (0.1-1 m/s), the intensity of the F=1 to 2 repumper drops rapidly and they fall into the F=1 state; some of them in mF= -1. Atoms are detected in fluorescence 5 mm downstream using a repumper probe that re-establishes a magneto-optical trap. The distance that the atoms travel in the dark is limited by far off-resonance photon scattering and background vapor pressure. Additionally, the waveguide is mounted horizontally to limit the effect of gravity, but a variation in probe fluorescence is observed when tilting the optics table on which the experiment is built. Accumulation of atoms in a dark state reservoir may eventually lead to a continuous version of an atom laser and atom interferometry.
- Publication:
-
APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 2002
- Bibcode:
- 2002APS..DMP.B2003R