Two-color CPT in a Single Cs Hyperfine Transition, Application in Magnetometry

We investigate the coherent population trapping effect occurring between the Zeeman sublevels of a given hy- perfine state of Cs when excited by a single-mode diode laser, which is frequency modulated in the kHz­MHz range. In the presence of a dc magnetic field, simultaneous excitation of pairs of ground-state magnetic sublevels to common excited mag- netic sublevels is performed. As a result, coherent population trapping resonance is detected at only a given modulation fre- quency, whose value gives a measure of the magnetic field. The parameters of the resonances are measured in order to determine the ultimate accuracy of the magnetic field measurement