Stabilization of the CO2 laser power by feedback controlling through an auxiliary electrode

The output power of the CW CO₂ laser is stabilized by the feedback control of the electrical discharge through an auxiliary electrode. The laser output is monitored by a HgCdTe detector, and to suppress the output fluctuations, the variable voltage is applied to the auxiliary electrode located near the grounded cathode. With this stabilization technique, the output power fluctuation is reduced to about one-tenth of that without the stabilization. The merit of this technique is that the auxiliary discharge is achieved in the very low voltage and current level compared with the main discharge