Optical excitation of the the B2Σ1/2+ → X2Σ1/2+ transition in the HgBr radical by consecutive interaction of HgBr2 vapor with the fourth (264 nm) and third harmonics (352 nm) of a neodymium glass laser

The feasibility of developing an HgBr laser utilizing the B²Σ_1/2⁺ → X²Σ_1/2⁺ transition by optical pumping of HgBr(X) radicals using the third harmonic of a neodymium laser was studied. The radicals were formed by photolysis of a mixture of HgBr₂ vapor with various buffer gases using the fourth harmonic of the neodymium laser. Under these conditions the luminescence was due to the B–X transition in the HgBr radical and its intensity was three orders of magnitude lower than that calculated from the absorbed third-harmonic energy, basing due to the B→X transition in the HgBr radical could not be achieved. When the mixture was exposed to the fourth-harmonic radiation, emission of the 7³S₁–6³P₂ (λ = 546 nm) mercury line was observed and the output pulse energy increased with increasing pump energy.