Scaling generalizations for a CO electric laser

Several scaling generalizations for a high-pressure CO electric-discharge laser (EDL) are presented and compared with experimental data from a pulsed e--beam-stabilized device. It is shown that the transient evolution of the CO laser medium is mainly dependent only upon the total energy deposition per CO molecule as a function of time. Results of theoretical calculations for CO/Ar mixtures are presented which show that, for temperatures 100 to 3000K, laser threshold occurs after E/p/sub CO/ approximately 0.5-1.0 J/1/torr (CO) has been deposited, and that steady state is attained after E/p/sub CO/ approximately 1.7-2.6 J/1/torr (CO) has been deposited. Experimental results for a variety of CO/Ar and CO/N2 mixtures confirm these predictions for a range of excitation rates. These generalizations make it possible to predict the temporal power characteristics of a large class of both pulsed and flowing cw CO lasers without resort to extensive computer calculations. Characterization of the gain saturation as a function of total radiation intensity was also investigated. Results indicate that, after attainment of steady state, the CO EDL saturates with threshold level like a simple two-level system, with a scaled saturation intensity of I/sub sat/ xi/p/sub CO2 / approximately 0.6 = 6.4 W/cm2/torr2 (CO) over the range of temperatures from 60 to 3000K (xi is the fraction of CO self-broadening to total broadening). (U.S.)