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The present-day ecological situation calls for lidar systems based on CO2 lasers. However, the spectral tuning range of a conventional CO2 laser is limited by a discrete set of oscillation lines on the regular bands 0001 - 1000, 0001 - 0200. Therefore, the possibility of using such lasers for atmospheric monitoring is limited and depends on accidental coincidence of radiation frequencies and absorption resonances of chemical compounds polluting the atmosphere. Besides, the presence of carbon dioxide in the environment leads to significant losses due to the absorption at its transmission in the atmosphere for considerable distances. We and other investigators obtained powerful radiation pulses at a sufficiently high efficiency in a TEA CO2 laser on nontraditional bands: the sequence (0002 - 1001, 0002 - 0201) and the hot (0111-1110) bands, which more than doubles the radiation spectrum of conventional CO2 lasers thus widening their potentialities for atmospheric monitoring. It is also important that the radiation of nontraditional bands practically is not absorbed by atmospheric carbon dioxide. In this paper, we present a UV-preionization TEA CO2 laser tunable over the lines of regular and nontraditional bands specially designed for atmospheric monitoring. Developing it, we took into account the fact that atmospheric monitoring places certain demands on lasers: high stability of output performances, a comparatively narrow oscillation line, low beam divergence, possibility of working in pulse-periodic regime. Besides, the laser has high energy performances and the widest possible spectral range of tuning. Special consideration was given to the real problem of tunable CO2 lasers -- automatization of the process of tuning over oscillation lines. On the basis of this laser a lidar system was created which has passed an in- the-field test to satisfaction. With its use small concentrations (at a tolerable-concentration level) of a number of gaseous pollutants was determined.
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