THE EFFECT OF HYDROGEN ADDITIVE ON POPULATION-DENSITIES IN THE AFTERGLOW OF BARIUM VAPOR LASERS

The effects of hydrogen additive on the performance and detailed kinet ics of a pulsed barium vapour laser operating with burst-mode excitati on are reported. Time resolved density measurements of significant ato mic and ionic barium states in pure neon buffer gas and in a Ne-H-2 mi xture show that the plasma relaxes between excitation pulses much more rapidly when hydrogen is present. The observed improvement in laser p erformance (65% increase in output pulse energy) under steady state (i .e. end of burst) conditions with hydrogen additive is directly attrib utable to improved pre-pulse conditions, resulting from cumulative eff ects of the enhanced plasma relaxation. The results and conclusions ar e relevant to other cyclic pulsed metal vapour lasers.