Abstract

For the observation of the cooperative radiation of the ensemble of atoms, the ensemble has either to be excited simultaneously by a delta-function pulse or the excitation has to propagate along the axis of the cigar shaped volume containing the ensemble ot atoms such that the superradiance pulse propagating along the axis meets always newly excited atoms. The latter arrangement results in the so-called swept-gain superradiance. The experimental realization requires that the atoms are excited by a pulse of resonant radiation of finite duration with the trailing edge sharply cut, propagating along the axis of the volume. The area of the exciting pulse is usually a multiple of π. Because of the difficulty of the excitation of a two-level system three-level atomic or molecular systems are used by exciting the common upper lever in one transition and the superradiance is observed on the other transition from the common level.

© 1992 IQEC