Investigation of the space–time characteristics of radiation from a pulsed CO2 laser in the presence of small-scale inhomogeneities of the active medium

A theoretical analysis is made of the mechanism of formation of small-scale inhomogeneities in the active medium of a pulsed electron-beam-controlled CO₂ laser. The mechanism is associated with an absolute hydrodynamic instability of the plasma of a non-self-sustained discharge. The results are reported of an experimental investigation of the influence of these inhomogeneities on the structure of the radiation in the far-field zone and on the divergence of a laser beam with an unstable telescopic resonator. It is shown that the growth of small-scale imhomogeneities during a pulse may increase considerably the divergence of the output radiation and its anisotropy.