Observation of sub-natural linewidths for cold atoms in a magneto-optic trap
Department of Physics, Indian Institute of Science - Bangalore
560 012, India
Corresponding author: firstname.lastname@example.org
Accepted: 17 October 2002
We have studied the absorption of a weak probe beam through cold rubidium atoms in a magneto-optic trap. The absorption spectrum shows two peaks, with the smaller peak having linewidth as small as 28% of the natural linewidth. The modification happens because the laser beams used for trapping also drive the atoms coherently between the ground and excited states. This creates “dressed” states whose energies are shifted depending on the strength of the drive. Linewidth narrowing occurs due to quantum coherence between the dressed states. The separation of the states and the linewidth depends on the trapping-laser intensity and detuning as predicted by this model.
PACS: 42.50.Gy – Effects of atomic coherence on propagation, absorption, and amplification of light / 42.50.Vk – Mechanical effects of light on atoms, molecules, electrons, and ions / 32.80.Pj – Optical cooling of atoms; trapping
© EDP Sciences, 2003