Coherent population trapping resonances in the presence of the frequency-phase noises of an exciting field (original) (raw)

The conditions necessary to implement a single-photon pulse source using quantum filtering based on the coherent population trapping phenomenon in N -systems of atomic levels are determined. The dependences of dark resonance characteristics on laser field intensities are experimentally measured in Rb vapor. These dependences define optimum intensity ratios and pulse durations of used laser beams, at which the system can efficiently operate as a single-photon quantum filter. (CPT) [1, 2] is a subject of basic research and applied developments in the field of precision spectroscopy [2], metrology [3], magnetometry , and light pulse storage and conversion using coherent excitations in an atomic medium . In [8], generalized dark states (GDSs) of CPT in the (atom + field) system were considered; it was shown that GDSs can arise in both classical (coherent light states) and quantized (n-photon or Fock light states) fields. Of most interest is the consideration of GDSs in atomic level systems forming the so-called N -chains during interactions with light fields . The N -chain is a sequence of L Λ systems complemented by one resonance transition. Due to this additional transition playing the role of a dark state decay channel, CPT does not occur in such a system in the classical field. Nevertheless, the theoretical consideration shows that GDSs can be formed in such systems as well.