Effect of the gas temperature of a high-power chemical oxygen-iodine laser on calculated small signal gain and output power

Rate equations describing the lasing kinetics of a high-power chemical oxygen-iodine laser were solved, taking into account the effect of gas temperature. The temperature rise resulting from deactivations was calculated at each computation step along the flow, with the temperature dependence of rate constants and of the heat capacitance of the total gas taken into account. It has been shown that the inclusion of the temperature effect has a significant influence on the calculated laser gain and laser output. The results of the present calculation verify the observation of surprisingly high gas temperature in the optical resonator in a previous experiment and indicate that the gas temperature of a subsonic, 1 kW-class chemical oxygen-iodine laser can easily be over 1000° C in the optical resonator unless a buffer gas is used to increase the heat capacitance.