Experimental comparison of the divergence of radiation from pulsed electron-beam-controlled CO and CO2 lasers

Measurements were made of the divergence of radiation from electron-beam-controlled CO and CO₂ lasers for closely similar pump conditions and resonator parameters. It was found that for the long pulse durations and the broad laser emission spectrum of the CO laser the divergence of the radiation due to individual vibrational–rotational transitions differed by a factor of three, the lowest divergence being realized after the end of pumping at the moment when a linear profile of the active medium density is established. Small-scale filamentary inhomogeneities were discovered during pumping of a CO-laser active medium cooled to cryogenic temperatures. The divergence of the CO₂ laser radiation was approximately the same as that of the lines from the CO laser having the greatest angular width.