Dependence of laser output on discharge starting voltage in longitudinally excited CO2 laser

Abstract

We investigated laser output characteristics depended on a discharge starting voltage, gas medium and a repetition rate in a longitudinally excited CO2 laser. A discharge tube with an inner diameter of 16 mm and a length of 80 cm was applied a high voltage with the rise time of about 200 ns. All laser pulse waveforms were a short laser pulse with a spike pulse and a pulse tail. In the 1:1:2 mixture of CO2/N2/He and at the repetition rate of 300 Hz, the laser energy was increased with the discharge starting voltage of up to 40.3 kV. However, in the 1:1:2 mixture of CO2/N2/He and at the repetition rate of 600 Hz, the laser energy was saturated with the discharge starting voltage of about 28.6 kV or more. The maximum energy was 14.2 mJ at a repetition rate of 600 Hz and a discharge starting voltage of 28.8 kV.