COMPUTATIONAL STUDY OF COLLISIONAL ENERGY-TRANSFER AND QUASI-CONTINUOUS POPULATION INVERSIONS IN LASER-PUMPED CA VAPOR

A computational study of population inversion between several pairs of excited states viz 3d4p F-3-4s3d D-3, 4s5s S-3-4s4p P-3 and 4s3d D-3- 4s4p P-3 in Ca vapor pumped on the 4s(2) S-1(0)-4s4p P-3(1) transition is presented. The main aim is to investigate the influence of various atomic processes in creating and sustaining the population inversion for long times after the excitation pulse. The delicate interplay betw een superelastic energy transfer to free electrons, energy pooling col lisions and cascaded recombination is particulary examined. It is note d that quasi-continuous population inversion can be readily excited on the 4s3d D-3-4s4p P-3 transitions; and under some conditions, also on the 4s5s S-3-4s4p P-3 transitions. Furthermore, inversion on the 3d4p F-3-4s3d D-3 transitions can also be excited for a considerable lengt h of time. The results may be useful in designing and developing quasi -cw metal vapor lasers.