A. Nagel, C. Affolderbach, S. Knappe, R. Wynands
Phys. Rev. A 61, 012504 (2000)
Abstract.
In a three-level Lambda system a bichromatic light field can induce a ground state coherence that leads to vanishing absorption of the bichromatic field. Although this coherence is between ground states only, in a real atom it can nevertheless be influenced by the hyperfine structure of the excited state. We present experimental results which show that for suitable detunings of the bichromatic field from optical resonance the specific contribution of each individual hyperfine level of the excited state can be distinguished through increased amplitude or width of the ground state coherence.
View a key figure:
| The fit curves through experimental points of dark resonance amplitude and width, together with dashed lines indicating the position of the pressure-shifted excited state hyperfine levels. The quantity on the horizontal axis is the laser detuning from the centroid of the optical resonance. | |