We study the temporal behavior of a three-level system (such as an atom or a
molecule), initially prepared in an excited state, bathed in a laser field
tuned at the transition frequency of the other level. We analyze the dependence
of the lifetime of the initial state on the intensity of the laser field. The
phenomenon we discuss is related to both electromagnetic induced transparency
and quantum Zeno effect.Comment: 10 pages, 3 figures. Contribution to Sixth Central-European Workshop
on Quantum Optics, Chudobin near Olomouc, Czech Republic, April-May 199
