Selection of dye vapors for use as active media and selection of buffer gases

A report is given of the results of measurements of the quantum efficiency η of the fluorescence emitted from 21 dyes in the vapor phase. A method is suggested for selecting buffer gases for use with dyes: this method is based on observations of the fluorescence and bleaching of vapors by an intense light flux. The results are given of a study of the influence of SF₆ and butene-2 on the fluoresence of paraterphenyl and l,4-di[2-(5-phenyloxazolyl)] benzene (POPOP) vapors. It is shown that the absolute values of η of vapors can be deduced from the measured constants of the exponential fall of the fluorescence intensity as a result of action of a constant light flux.