Quasi-cw laser action through pulsed laser pumping of metastable states in dense vapors

Abstract

A new scheme is proposed for exciting laser action employing resonant pumping of metastable states together with collisional energy transfer in hot and dense vapors. The specific case of Ca is presented here as an example. Large population inversions and gain on Ca 4s5s 3S 1−4s4p 3P 2,1,0 transitions at 6162.17 Å, 6122.22 Å and 6102.72 Å are reported. A unique feature here is that these population inversions are maintained over long periods of time after the exciting laser pulse, extending from 90 μs in the case of J=0 state up to 250 μs in the case of J=1 state. This offers an unusual possibility of making quasi-continuous laser sources from short pulse excitation.