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Q: Quantenoptik und Photonik
Q 40: Laserspektroskopie
Q 40.5: Talk
Thursday, March 25, 2004, 17:30–17:45, HS 204
Simultaneous electromagnetically induced transparency and absorption in a closed transition — •Luca Spani Molella, Rolf-Hermann Rinkleff, and Karsten Danzmann — Max-Planck-Institut für Gravitationsphysik und Institut für Atom- und Molekülphysik, Universität Hannover, Callinstraße 38, D-30167 Hannover.
Aim of this work is to provide insight into some new phenomena which occur in a typical EIA (electromagnetically induced absorption) transition. The F=4 to F’=5 transition of the Cs D2 line is analyzed with a probe and a coupling laser. A third laser allows simultaneous measurement of the dispersion of either the probe or the coupling laser (heterodyne interferometer). At resonance the probe laser shows EIA, while the coupling shows simultaneously electromagnetically induced transparency. These results are observed for the first time and are obtained in a range of several decades for the power of both the probe and the coupling laser. Since our apparatus is highly sensitive for dispersion measurements, we are able to present the first results of the coupling laser (parametric) dispersion as a function of the detuning of the probe laser in the same closed degenerate two level transition. The coupling laser shows positive parametric dispersion, which grows to a maximum and then decreases as a function of laser powers. The dispersion of the probe laser around the EIA peak is on the contrary negative but shows a similar behaviour as a function of the laser powers. A brighter negative dispersion signal superimposed on the previous one is observed at low laser powers.