Laser Cooling of Atoms

Philip H. Jones, Onofrio M. Maragò, Giovanni Volpe

William D. Phillips

In 1988, before the beginning of the current contract period, our group discovered that sodium atoms could be laser cooled well below the lower limit (the 'Doppler limit') predicted by the then generally accepted theory. Two main consequences of that discovery were a revamping of the theory of laser cooling and a renewed interest in the applications of laser cooling because of the far lower temperatures. Both of these effects are continuing in full force today, and this report is in large part a record of our group's continuing involvement in the new developments in laser cooling during the past three years. The work of the NIST laser cooling group falls functionally into the categories of: investigating laser cooling mechanisms; studies of collisions between laser cooled atoms; development of new trapping techniques for neutral atoms; study of the fluorescent spectrum of laser cooled atoms; manipulation of atoms and atom optics; development of coherent sources of vacuum ultraviolet light for laser cooling and high resolution spectroscopy; application of laser cooling and trapping technology to atomic frequency standards.

N. Beverini, S. De Pascalis, E. Maccioni +5 more

Laser cooling in a Mg atomic beam is reported for the first time to our knowledge. Previous cooling experiments were performed by using visible or infrared lasers. The Mg atoms were cooled by using an intracavity frequency-doubled dye laser at 285 nm to reach the resonant (1)S(0)-(1)P(1) transition. Evidence of laser cooling was obtained even with the limited available laser power ( approximately 1-2 mW).

Steven Chu, Carl Wieman

Steven Chu, Mara Goff Prentiss, A. Cable +1 more

Mark G. Raizen, Dmitry Budker, Simon Rochester +2 more

We propose an alternative method to laser cooling. Our approach utilizes the extreme brightness of a supersonic atomic beam, and the adiabatic atomic coilgun to slow atoms in the beam or to bring them to rest. We show how internal-state optical pumping and stimulated optical transitions, combined with magnetic forces, can be used to cool the translational motion of atoms. This approach does not rely on momentum transfer from photons to atoms, as in laser cooling. We predict that our method can surpass laser cooling in terms of flux of ultracold atoms and phase-space density, with lower required laser power. © 2014 Optical Society of America OCIS codes: (020.0020) Atomic and molecular physics; (020.7010) Laser trapping; (020.7490) Zeeman effect; (020.3320) Laser cooling.