Investigation of the effects of bromine and hydrogen bromide additives on copper vapour laser performance

We report on a detailed study of the effects of bromine and hydrogen bromide buffer-gas additive on the electrical and lasing characteristics of a conventional, high-temperature copper vapour laser. At standard buffer gas flow rates HBr-Ne mixtures produced relatively small improvements in output power, however, larger increases in output power were observed at elevated HBr-Ne flow rates. Added HBr also significantly modifies the spatio-temporal characteristics of laser output, increasing the pulse duration by a factor of 2 while also improving the radial intensity profile. This result has important implications for improving the extraction of high beam quality output from devices employing high magnification unstable resonators.