High-power CO lasers in Russia

The research-and-development effort on CO lasers and applications of these lasers in Russia are reviewed. Various types of cw, pulsed, and periodic-pulse CO lasers have been developed in various laboratories. Sealed-off, water-cooled cw CO lasers with an output power of 5–10 W, pumped by a self-sustained electric discharge, are being used successfully in the manufacture of electronic devices and in medicine. The output power of fast-flow cryogenic cw CO lasers with a self-sustained discharge ranges up to ~1 kW. The use of electron-beam pumping has made it possible to develop pulsed electron-beam-sustained (EBS) CO lasers with an energy up to ~1 kJ and also to develop cw and periodic-pulse EBS CO lasers with a power of 10 kW and an efficiency up to ~40%. Research on pulsed electron-beam-sustained CO lasers has been the scientific foundation for the construction of CO laser systems of the (master oscillator)-amplifier type and periodic-pulse CO lasers. A CO laser system with an output energy ~200 J and an output beam divergence of 2·10^–4 rad has been developed. Requirements on the effective gain in the active medium and on the transport through atmospheric air of multifrequency output pulses from CO laser with various spectral and temporal characteristics have been formulated. A supersonic EBS CO laser with a peak power ~10⁵ W and a 10-kW periodic-pulse EBS CO laser with subsonic flow have been developed. The latter laser generates pulses with an energy ~100 J and a repetition frequency up to 100 Hz. The EBS CO lasers with injection of the laser mixture in the liquid phase are discussed. Lasers using nuclear ionization of the active medium are also discussed.