Operational characteristics of a TE CW CO2laser with a DC auxiliary discharge

This paper describes a TE CW CO2laser with a special gas flow scheme and an auxiliary discharge configuration. In this laser system, mixed gas was forced to flow through a structure of square tubes with meshes on both sides. An array of auxiliary electrodes was added to produce a dc auxiliary discharge between these electrodes and a tubular cathode. By introducing these structures, uniformity and stability of the main discharge could be significantly improved, and more electrical input power could be deposited into the laser gases at higher pressures and higher discharge currents. An output power exceeding 3000 W/m was obtained at a gas mixture of CO:CO2:N2:He = 4:10:25:40 and a total pressure of 7.9 kPa. Without the auxiliary discharge, the maximum output power was less than 1600 W/m, and a stable discharge could not be obtained at a pressure above 4 kPa. The spatial distributions of unsaturated gain along the direction of gas flow and contours with constant gain were also drawn. By introducing molecular sieve 3A, the system could be operated continously over 15 h under sealed-off conditions.