Effects of oxygen contamination on gasdynamic laser performance

The effects of oxygen contamination in the fuel mixture of a shock tube-driven gasdynamic laser were studied. Five mixtures of CO2, N2, O2, and H2O were used (CO2 and H2O were held constant; O2 ranged from 0 to 40% in 10% increments). The small-signal gain coefficient for each of three CO2 P-branch rotational-vibrational transitions was measured, and a rotational line (J-line) scan analysis was used to reduce the data. Both the gain and the energy available for lasing were found to decrease linearly as O2 was increased. The experimental findings are in good agreement with theory.