<title>Q-switched low-pressure CO2 laser</title>

Abstract

Q-switched low pressure CO2 lasers allow the production of maximum laser pulse power and both high average laser power at high pulse repetition rates. The laser beam power can be calculated by a six temperature model including rotational relaxation, intramode and intermode vibrational energy exchange. A Q-switched CO2 laser oscillator amplifier systems consisting of a DC discharged, wavelength tunable and diffusion cooled oscillator and a microwave excited amplifier is described. By a mechanical Q-switching of the oscillator laser pulses with a pulse repetition rate of 4 - 200 kHz and TEM00 beam quality can be produced. After amplification the peak power reaches 0.9 MW at a pulse repetition rate of 10 kHz and 0.2 MW at 100 kHz repetition rate. The pulse duration (FWHM) is about 0.2 microsecond(s) . The maximum average power of 7 kW in the Q-switched mode reached nearly the maximum cw laser power of 10 kW (with TEM00 beam quality). The laser pulse duration can be shortened by the combination of cavity dumping and electro-optical Q-switching. This pulsed operation leads to laser pulses with 35 ns pulse duration and 1.9 MW maximum power at a pulse repetition rate of 10 kHz and an average laser power of 0.8 kW. The self-oscillation of the oscillator amplifier system can be suppressed by an optical shutter between oscillator and amplifier.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.