ELECTROMAGNETIC-FIELD INDUCED SWITCHING OFF OF RADIATION TRAPPING

We report on the observation of radiation trapping removal by the appl ication of a strong laser pulse which couples the upper level of the i nvolved atomic transition to a third higher level. The process was stu died using the fluorescent pulse detected in concomitance with the las er application. A spectroscopic analysis was performed in a time gate comparable to the pulse duration in correspondence to three different atomic densities. The spectra were compared to theoretical curves obta ined using the density matrix formalism. (C) 1997 Elsevier Science B.V .