X 2Σ→B2Σ absorption band of HgBr: Optically pumped 502-nm laser

Abstract
The X2Σ+1/2B2Σ+1/2 absorption band of HgBr has been observed in the afterglow of a pulsed Ne‐N2‐HgBr2 discharge. Peaking in the ultraviolet (UV) near 350 nm, this continuum degrades slowly to the red and at 410 nm the absorption coefficient is 30% of its maximum value. Upon exciting the XB band with an XeF (351 nm) or frequency tripled Nd:YAG (355 nm) laser, intense lasing is observed in the blue‐green (λ∼502 nm). For λpump=351 nm, the energy conversion efficiency (UV to green) is 22% which corresponds to a photon conversion efficiency of 32%. The quantum efficiency for this four level system is 71%.