METHOD OF INTRARESONATOR ABSORPTION GAS SPECTROSCOPY Russian patent published in 1997 - IPC

FIELD: spectroscopic methods. SUBSTANCE: method is designed for determining small concentrations of gas in unknown gas sample and also for determining a series of spectroscopic parameters of this gas from absorption line shape provided the chosen gas has absorption lines in ultraviolet region of spectrum. Invention consists in that, in absence of a cell with gas sample in laser resonator, exciting emission is formed from one of two components of bimodal laser generation with frequencies ω₁ и ω₂ and I_ω1 and intensities I_ω2 and ω₁ by way of intraresonator duplication of emission with frequency I_ω1. Afterwards a cell with unknown gas sample is placed in resonator, exciting emission is passed through cell, and two values of intensity ratios I_ω2 with two different pressure values p₁ and p₂ in cell are recorded on resonator outlet. From these values, concentration of chosen gas in initial gas sample is determined using known relationships. EFFECT: improved accuracy of method.