Competition of dark states: Optical resonances with anomalous magnetic field dependence - art. no. 051802

A different type of optical resonance has been observed in Doppler-free sat urated absorption spectroscopy when the pump beam has elliptical polarizati on slightly deviating from the sigma (+) and the probe has sigma (-) polari zation. An interpretation in terms of competition between two trap states a nd a dressed-atom model is presented. The observed extreme sensitivity of t he resonance frequency to the external magnetic field is attributed to the "scissors effect" of the dressed states' crossing point.