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 NO 2 , SiF 4 , CO 2 , ClO 2 , F 2 CO, FNO, FNO 2 , and NF 3 of which only NO 2 , and ClO 2 , in the case of XeF, appreciably absorb at the laser wavelengths. These latter species were created from the air impurities in the F 2 and He gases and their creation acts to deplete the F 2 donor. For ArF, the lifetime of the gas could be considerably extended by circulating the gas through a liquid N 2 trap. For the rare-gas chlorides, no discharge induced species were spectroscopically detected although AlCl 3 powder was formed in the laser tube. A more F 2 compatible laser tube than glass and high purity F 2 should be used for long lived rare-gas fluoride operation.