POPULATION OF METASTABLE BARIUM ASSOCIATED WITH CONICAL EMISSION

By illuminating barium vapor with a cw broadband laser tuned to the bl ue of the 6s(1)S(0) --> 6p(1)P(1) transition we have observed a red-sh ifted conical emission. For the same laser detuning we measured a subs tantial population of the metastable barium levels 5d(3)D(J). The spat ial population distributions appear to be much broader than in the cas e of zero detuning. The implications of these results on the existing models for conical emission are discussed. (C) 1997 Elsevier Science B .V.