Novel magnetic-spiker sustainer excitation circuit for a multijoule TE CO₂ laser

Successful operation of a multijoule output TE CO₂ laser using a new magnetic-spiker sustainer excitation circuit is reported. The use of the new excitation circuit has resulted in a significant reduction (~90%) in the amount of sustainer pulse energy that has to pass through the magnetic switch. In addition, the new circuit technique allows operation of the discharge at reduced voltage (~50%) and extends the range of excitation current pulse durations (up to ~7 µs) over which arc-free discharges can be formed. The laser has produced a typical output of 5 J at an overall efficiency of ~13% from a helium-free gas mixture at a pressure of 400 mbar.