Gas composition and lifetime studies of discharge excited rare-gas halide lasers

A spectroscopic study has been made of the stable species produced in rare-gas halide laser discharges. Molecules observed to be created in rare-gas fluoride discharges were NO2, SiF4, CO2, ClO2, F2CO, FNO, FNO2, and NF3of which only NO2, and ClO2, in the case of XeF, appreciably absorb at the laser wavelengths. These latter species were created from the air impurities in the F2and He gases and their creation acts to deplete the F2donor. For ArF, the lifetime of the gas could be considerably extended by circulating the gas through a liquid N2trap. For the rare-gas chlorides, no discharge induced species were spectroscopically detected although AlCl3powder was formed in the laser tube. A more F2compatible laser tube than glass and high purity F2should be used for long lived rare-gas fluoride operation.