Study of the B 2Sigma(+) - X 2Sigma(+) emission spectra of HgX (X = Cl, Br, and I) in a dc glow discharge

The emission spectra of the HgX B - X (X = Cl, Br, and I) transition, relevant in the technology of blue-green lasers, are studied in order to understand further the HgX (B 2Sigma+) formation mechanism under various buffer gases and discharge conditions. The resonant energy transfer and Penning process in the glow discharge of HgBr + N2 and HgX2 + Ar mixture are found to have comparatively large reaction cross sections. The stimulated cross sections, saturation intensities, and laser oscillation thresholds for these transitions are calculated from the experimental data. The possibility of achieving higher lasing efficiency and CW operation is investigated.