CALCULATION OF THE TRANSITION ENERGIES OF THE F2+-O2- LASER-ACTIVE COLOR-CENTERS IN SODIUM-CHLORIDE

The absorption and the emission spectra of the oxygen-perturbed F2+ color center occurring in NaCl:OH- color center lasers have been studied quantum mechanically to test the validity of the proposed center configuration consisting of an F2+ center adjacent to an O2- anion. Ignoring all the lattice effects and by modelling the F2+ color center as a hydrogen molecular ion embedded in a dielectric continuum, the effect of the adjacent oxygen ion has been treated as a perturbation and the resulting shifts in transition energies have been calculated using first order perturbation theory. Remarkably good agreement between the experimentally measured and theoretically predicted shifts has been obtained for most of the states considered, supporting the validity of the proposed center configuration.