Laser cooling below the one-photon recoil by velocity-selective coherent population trapping
Abstract
We present a new laser-cooling scheme based on velocity-selective optical pumping of atoms into a nonabsorbing coherent superposition of states. This method has allowed us to achieve transverse cooling of metastable 4He atoms to a temperature of 2 μK, lower than both the usual Doppler cooling limit (23 μK) and the one-photon recoil (4 μK). The corresponding de Broglie wavelength (1.4 μm) is larger than the atomic transition optical wavelength.
- Publication:
-
Physical Review Letters
- Pub Date:
- August 1988
- DOI:
- Bibcode:
- 1988PhRvL..61..826A
- Keywords:
-
- 32.80.Pj;
- 42.50.Vk;
- Optical cooling of atoms;
- trapping;
- Mechanical effects of light on atoms molecules electrons and ions