A study on CO2 gas dynamic laser driven by methane-air combustion

The CO2 gas dynamic laser driven by methane-air combustion in an unsteady flame propagation combustor was proposed for the purpose of industrial application. The effect of coexisting H2O with high concentration on the population balance between CO2(001) and CO2(100) levels of vibration-rotation modes was theoretically analyzed The analysis showed that the population inversion between the two levels can take place with the methane-air combustion at stoichiometric ratio if the gas flow is accelerated to Mach number 5.0. The population inversion was confirmed by the experimental measurement of the small-signal gain carried out applying the unsteady flame propagation combustion. High emission power of about 2.5 kW with the path length of 0.3 m may be expected from the magnitude of the gain.