Ultrahigh-Contrast Saturated-Absorption Resonance to Enhance Stability of CPT Atom Clocks

International audienceThe results of detailed experimental and theoretical investigations of new nonlinear effect in the field of saturated-absorption spectroscopy of atom vapours are presented. The effect consists in observation of a high-contrast natural-linewidth absorption spike when 133Cs atoms are being irradiated by the bichromatic counterpropagating laser beams. The results obtained can be useful in various fields of modern laser physics and applications where saturated-absorption resonances are used. For instance, the effect has been already implemented in the coherent-population-trapping atom clocks to enhance stabilization of optical frequencies and to improve stability of the clocks on the whole