Experimental determination of the saturation parameter of a cw electric-discharge CO laser

The following parameters were determined for a cw electric-discharge CO laser, using a mixture of CO–N₂–He–Xe–O₂ for both continuous-flow and sealed-off operation: the saturation power P_s saturation parameter I_s unsaturated gain, internal optical losses in the resonator, and ultimate power extracted from unit volume of the active medium. The dependence of I_s, on the pressure of the lasing mixture was investigated and it was established that I_s displays a tendency to saturate at pressures of 22-23 Torr. It was found that the values of P_s and I_s are 3–4 times lower for sealed-off than for continuous-flow operation. The output powers obtained from the resonator in these experiments were ~40% of the ultimate values.