DOUBLE-COLOR EXPERIENCE IN MAGNESIUM - EX CITATION AND COUPLING OF AUTOIONIZING STATES USING UV SOURCES

We study double-resonance processes in Magnesium. One laser is used to ''pump'' the 3p(2) resonance through two-photon absorption from the 3 s(2) fundamental state of Mg. A second laser couples the 3p(2) Se-1 re sonance to the 3p3d (1)p(0) narrow autoionizing state. In the experime nt the ionization rate is measured in two different situations; with a fixed frequency for the pumping (coupling) laser and varying the freq uency of the coupling (pumping) laser. In agreement with the experimen tal findings, a theoretical study shows that, for particular frequenci es of the laser fields, a situation of coherent trapping occurs with a partial stabilization of the system.