Active medium of molecular CO2 and CO lasers as a nonlinear component of a phase-conjugating mirror

An experimental study of a four-wave interaction in the active laser medium was made for long (10–10³ μs) pulses emitted by electron-beam-controlled-discharge CO₂ and CO lasers. Linearly polarised probe radiation from a CO₂ (CO) laser was directed into the intracavity inverted medium of the laser itself. The radiation reflected back by the active medium was recorded in the near-field and far-field zones. Phase conjugation was confirmed by reconstruction of the spatial pattern of the radiation field in the near-field zone and of the angular divergence of the radiation in the far-field zone. The energy coefficient representing phase conjugation by reflection reached 2% for the CO₂ laser and 0.2% for the CO laser. The time dependence of the phase-conjugation power coefficient was analysed.