SUPERFLUORESCENT TRANSITIONS IN AN EXTERNAL MAGNETIC-FIELD

Polarisation properties of the superfluorescence in the near-infrared regime have been investigated between high-lying levels of Sr and Ba u nder the influence of a static homogeneous external magnetic field. In some transitions the time-resolved measurements show a change of the polarisation of the superfluorescence depending on the magnetic field strenght. In suitable experimental conditions intensity modulations we re observed. These were assigned as Zeeman quantum beats or indirectly observed Zeeman superfluorescent beats. The experimental findings of superfluorescence in two-level, three-level, or multi-level configurat ions in dependence on the magnetic field strength can be explained wel l in a semiclassical model of multi-level superfluorescence.