Output-power fluctuations of flowing-gas CO2 lasers with unstable resonators

An experimental study was made of the influence of different factors on the stability of the output intensity of a flowing-gas CO₂ laser with an unstable resonator. The measured amplitude-frequency characteristics of the intensity fluctuation spectrum had resonance peaks at multiples of the frequency corresponding to the transit time of the gas to the optic axis of the resonator. A rise in the efficiency of the laser system was found to be accompanied by an increase in the amplitude of the fluctuations of the radiation intensity.