Characteristic features of tuning a TEA CO2 laser having an unstable resonator by an external signal and an intracavity absorber

An experimental investigation was made of the characteristic features of using an external signal to tune the emission spectrum of a TEA CO₂ laser, having an unstable resonator, from the strongest 10P(20) line to one of the neighboring lines, right up to the 10P(10) line. The problems discussed include optimization of the parameters of a master oscillator and of a regenerative amplifier, including introduction into the amplifier resonator of gases exhibiting selective absorption of the spectral lines of the CO₂ molecule.