Detection capabilities of different molecular lasers in infrared spectroscopic diagnostics of multicomponent gas mixtures

摘要

The capabilities of different molecular gas lasers in infrared absorption diagnostics of multicomponent mixture are evaluated and compared. Extended sets of vibration-rotational emission lines are used for the following lasers: CO_2, HF, DF, NH_3, N_2O and CO (including fundamental and first overtone transitions). Analytical frequencies are selected for all indicated lasers using spectroscopic databases in order to detect organic and inorganic pollutants using either low- or high-resolution spectra. Comparison of absorption in the atmosphere is made for frequencies of different lasers. Absorption spectra are simulated for 38 component gas mixture. Quantitative parameters characterizing the sensitivity and the selectivity of specific gas detection are calculated and compared: minimum detectable concentration, partial sensitivity, partial selectivity. It is found that NH_3 and CO lasers presently have the best spectroscopic detection characteristics.