High-gain Soft-x-ray Pumped Photoionization Laser in Zinc Vapor

Large inversion densities in Zn+ have been produced by photoionizing inner #x2010;shell d electrons with the broadband soft #x2010;x #x2010;ray flux from a 1.06 #x2010; #x3bc;m laser #x2010;produced plasma. This pumping scheme is an effective technique for rapidly producing large population densities (5 #xd7;1013 cm-3) in the 3d9 #x2009;4s2 #x2009;2D5/2 upper laser level. These large densities (a) produced laser action on a two #x2010;electron transition from the d #x2010;electron manifold to the outer #x2010;electron manifold at 7478 #xc5;, (b) allowed the isotope shifts on this relatively weak transition to be measured, and (c) may eventually be transferred to other high lying states in Zn+ to produce vacuum ultraviolet lasers.