Excimer-pumped four level blue-green solid state laser

摘要

An efficient, four-level, blue-green, excimer-pumped laser which is operable at room temperature. The laser element includes a CaWO. sub.4 crystal which has been codoped with trivalent thulium activator ions and divalent ytterbium sensitizer ions. Energy is transferred from the absorbing Yb.sup.2+ ions to the Tm.sup.3+ ions and the laser transition is from the .sup.1 D.sub.2 multiplet to the ground .sup.3 F. sub.4 of the Tm.sup.3+ ion. This transition terminates on an excited state; therefore, the laser action is four-level.