Operation of arc-heated gasdynamic CO2 laser at 16.4-18.6 microns

For a gasdynamic laser operated on CO2 coupled-mode transitions, observations are made of quasi-CW and CW laser action with a wavelength of 18.4 microns and of quasi-CW action in the spectral range 16.4-17.2 microns. It is found that neither the possible impurities from the arc source nor the gas flow nonuniformity at the nozzle outlet cause destruction of the population inversion between CO2 coupled-mode levels in these devices. The high specific power (approximately 30 kW/kg) and intercavity power density (approximately 3 kW/sq cm) estimated for a wavelength of 18.4 microns suggest that an 18.4-micron CO2 gasdynamic laser is comparable to the 10.6-micron CO2 gasdynamic laser in its power output. Lasing on CO2 coupled-mode transitions is obtained on devices designed for investigating conventional CO2 gasdynamic lasers (lambda = 10.6 microns).