Kinetics of processes in a waveguide CO2 laser with controlled output pulse shape

A kinetic model was developed of a pulse-periodic waveguide CO₂ laser excited by a non-self-sustained discharge, its gas being preionized by short high-voltage pulses. Rectangular radiation pulses having a duration of 10–30 μs and a pulse repetition frequency of 15–50 kHz were generated by varying the reflection coefficient of the exit mirror with time according to a parabolic law in synchronism with the preionization pulses and thereby dynamically controlling the Q factor of the waveguide resonator. Numerical modeling methods were used to determine the characteristic laser parameters. Thus, for example, in the square-waveform regime at a frequency of 50 kHz the average laser output power exceeded 30 W.