High-pressure carbon dioxide electrically excited preionization lasers

A review is given of the results of theoretical and experimental investigations of electrically excited preionization gas lasers in which the pressure in the working mixture may reach tens of atmospheres. The method of preionization by external agency is considered and it is reported that, under optimal conditions, practically 100% of the electrical pump energy can be converted into the energy of molecular vibrations. Experimental results are quoted to show that the output power of electrically excited preionization lasers increases proportionally to the square of the gas pressure. The results are given of experimental investigations of the threshold and output characteristics as well as of the efficiency and gain of electrically excited preionization (and, particularly, electron-beam-controlled) carbon dioxide lasers. High-pressure lasers of this kind are promising sources for thermonuclear fusion, selective stimulation of chemical reactions, and industrial processing. Some numerical data are given on the various modes of operation of electrically excited preionization carbon dioxide amplifiers and oscillators. The characteristics of some high-power laser units are briefly described. A discussion is given of potential application of the electrical preionization method in the excitation of the vibration-rotational molecular levels (CO$_2$, CO, N$_2$O, NO, N$_2$, HF, and others) and of electronic state (N$_2$, H$_2$, CO, Cu, Pb, Xe$_2$, and so on). The review is based on papers published up to May 1973.