RINGING IN THE RESONANCE FLUORESCENCE-SPECTRUM OF A DRIVEN 2-LEVEL ATOM UNDER BICHROMATIC EXCITATION IN A BROAD-BAND SQUEEZED VACUUM

We present analytical results for the steady-state resonance fluoresce nce spectrum produced by a driven two-level atom excited under two str ong coherent fields in the presence of a broadband squeezed vacuum. He re the central frequency of the squeezed vacuum is considered to be re sonant as well as off-resonant with the average driving field frequenc y while maintaining resonance between the atomic transition frequency and the average driving field frequency. We observe a ringing phenomen on in the fluorescence spectrum due to the small frequency difference in the bichromatic field and this phenomenon is found to be sensitive to the detuning of the carrier frequency of squeezed vacuum with respe ct to the central frequency of the bichromatic field. [S1050-2947(98)0 0810-5].