Atomic Coherences and Level-Crossings Physics

V�ronique Bommier

Gerd M. Hermann, Kay Niemax

I. INTRODUCTION A. Level-Crossing Phenomena and the Effect of Coherent Forward Scattering Coherent forward.scattering (CFS—used for the physical effect as well as for the approach of coherent forward scattering spectroscopy) has been investigated first in connection with atomic resonance radiation phenomena like double resonance and level-crossing effects.1 The very early level crossing has been measured in lateral fluorescence in a weak magnetic field.2 This “zero-field level crossing” in lateral detected resonance fluorescence is called “Hanle effect”3 and can be classically described by the model of an atomic oscillator, emitting during its Larmor precession with respect to the applied magnetic field (Figure 1).

H. J. Beyer, Karl Blum, R. Hippler

Karen Southwell

Olga A. Kocharovskaya, Yevgeny V. Radeonychev, Paul Mandel +1 more

We describe the physical effects emerging in three-level atoms as a result of a drastic modification of the relaxation processes under the action of a strong coherent field when one of two dynamic Stark levels crosses a nearby atomic state.

W. Pötz, Ulrich Hohenester, Jaroslav Fabian