Excited mercury atoms in an electrodeless discharge are exposed to high-power radiation at 5289 Å obtained by frequency-doubling the output of a Q-switched Nd : glass laser. A very weak line is detected at 4250 Å and described to a Raman transition from the 63 P2 to the 63 P1 state.
Isotopically selective resonance ionization of mercury atoms has been accomplished by three-step excitation via the 6 3P1 and 8 1S0 excited states. Three collinear beams, respectively 254, 286, and 532 nm, from two dye lasers and a pulsed neodymium:yttrium aluminum garnet (ND:YAG) pump laser, were passed through a closed mercury vapor cell containing electrodes to which the ions were drawn by an electric field. The ion current and the 254-nm fluorescence radiation were measured as a function of laser wavelengths. Hyperfine structures for the 254- and 286-nm transitions were observed.