Transmission of tropospheric radiation of lasers on molecules of different carbon dioxide isotopes

CO2 lasers operating in different lines of the bands 00 sup 0 1-10 sup 0 0 and 00 sup 0 1-02 sup 0 0 of molecules of different carbon dioxide isotopes are coming into increasing use for remote measurements of the parameters of the gas composition of the atmosphere. Their generation spectrum coincides with the window of relative atmospheric transparency 8-13 micro m. However, the solution of many problems requires a reliable knowledge of the parameters of molecular absorption of the emission of CO2 lasers in the troposphere. The theoretical possibility of generation of laser radiation in 960 lines of seven CO2 isotopes has been demonstrated. In order to fill this gap partially the authors give the results of computations of the transmission of laser radiation on seven isotopes of carbon dioxide by the tropospheric layer during summer in the middle latitudes of the northern hemisphere. The most transparent microwindow has a transmission of 80-85% in the region 10 micro m, where losses for the most part are determined by the continuous absorption of water vapor. The computations make it possible to analyze the contribution of each gas to the total attenuation of the radiation of CO2 lasers by the atmosphere due to molecular absorption.