Optimization of the parameters of radiation emitted by Model 143 pulse-periodic CO2 laser

The small-signal gain of the active medium in a pulse-periodic CO₂ laser was determined. The resonator parameters were optimized. The use of a germanium Fabry–Perot etalon as the exit mirror made it possible to increase the output energy from 0.4 to 1.2 J per pulse. An analysis was made of various ways of constructing selective resonators with diffraction gratings. It was found that when radiation was coupled out using the zeroth diffraction order and the resonator was optimized by rotating the direction of the polarization of the radiation in the course of tuning of the emission frequency, there were additional losses in a Brewster window due to a change in the polarization azimuth on reflection from a diffraction grating.