Characteristics of a transverse-flow CO laser excited by RF-Discharge

We have developed a compact, efficient kW-class CO laser excited by transverse radio frequency (RF) discharge. The discharge and output characteristics of the RF-excited CO laser were investigated and were compared with those of the DC-excited one. The RF discharge power at 13.56 MHz was supplied to a discharge volume of 40H/spl times/35W/spl times/280L (mm/sup 3/). Utilization of the RF excitation instead of the DC excitation enhanced the maximum input power, the electrical conversion efficiency and the beam quality. Six gas conditions (pressure, temperature, flow speed, and the concentrations of CO, N/sub 2/, and O/sub 2/) were chosen as the experimental parameters. The optimum values of the gas parameters to maximize the output power were 50 torr, 200 K, 17 m/s, 5%, 12% and 0.4% respectively. The maximum output power obtained was 1.32 kW, with an electrical conversion efficiency of 27% and a slope efficiency of 39%. The specific laser power, which characterizes the scaling law of a transverse-flow laser, was 4.6 kW/m for the length, and 3.3 W/cm/sup 3/ for the volume.<
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