Influence of the excitation field frequency on the operation of an rf-pumped waveguide CO2 laser

An investigation was made of a sealed waveguide CO₂ laser excited by an rf field at three fixed frequencies: 40,93, and 152 MHz. The pump power at the different frequencies was kept constant by controlling the circuit matching the impedances of the laser and the rf-field source. For a specific laser model, an optimal excitation frequency range (93 MHz) was established by trial and error. This frequency range was characterized by the lowest value of the discharge parameter E_eff /N and by the maximum laser output power (6 W). An analysis was made of the characteristic features of rf discharges due to an additional control parameter, namely the frequency of the excitation field.