INFLUENCE OF DISCHARGE PROPERTIES ON CO2 LASER GAIN

Abstract

The radial variation of small‐signal gain α₀ at 10.6 μm was measured in a cylindrical, electrically excited CO₂ laser amplifier. The radial‐gain profile changed markedly with increasing current. This was interpreted in terms of the dependence of gain on electron density and gas temperature. A modified Schottky analysis of the positive column was used to characterize the discharge properties. Values of electron density and gas temperature thus obtained were combined with the reported dependence of α₀ on these parameters permitting calculation of the radial variation of α₀. Comparison of calculated and measured values of α₀ yielded good quantitative agreement, indicating that the analytical model accurately represents the features of the important physical phenomena which influence small‐signal gain. These results emphasize the necessity of maintaining a low gas temperature to achieve maximum laser performance.