HIGH-FREQUENCY TEMPORAL STRUCTURE OF LASER AND PHASE-CONJUGATED SIGNALS IN INTRACAVITY DEGENERATE 4-WAVE-MIXING OF RADIATION FROM ELECTRON-BEAM-CONTROLLED DISCHARGE CO2 AND CO LASERS IN THEIR ACTIVE MEDIA

The high-frequency temporal structure of probe-laser and phase-conjuga ted signals, generated in the course of degenerate four-wave mixing of long pulses from CO2 and CO lasers in their own inverted media, was i nvestigated experimentally with nanosecond resolution throughout the w hole pulse. Single-frequency (corresponding to one vibrational-rotatio nal transition) and multifrequency pulses of similar to 10-20 mu s and similar to 200-300 mu s durations, generated respectively by electron -beam-controlled discharge CO2 and CO lasers, had a complex temporal d ynamics with a depth of modulation up to 100%. In one round-trip perio d (similar to 100 ns) the pulses from these CO2 and CO lasers consiste d of several spikes (free-running mode) or of one spike (self-mode-loc king with the aid of a plasma mirror) of tau(0.1) similar to 10 ns dur ation. The temporal dynamics of the phase-conjugated signal also had a complex structure, differing from the probe signal structure over lon ger (in excess of 100 ns) and shorter time intervals. The relative inf luence of the amplitude and phase mechanisms of the formation of trans ient diffraction gratings in the active medium, and also the influence of large-and small-scale diffraction gratings, and of the temporal sy nchronism on the dynamics of the phase-conjugated signal were consider ed.