Experimental investigation of O2 molecules distribution over vibrational levels in O2 (А1.G)-I medium

Vibrationally excited oxygen in active medium of chemical oxygen-iodine laser (COIL) using emission method was detected for the first time. It is shown that because of fast EE-exchange of energy the mean number of vibrational quanta per one molecule in each of a component O2(. g 3У X ), O2( g 1Д a ) and O2( +.g b1 ) is approximately equal and exceeds 30 % in active medium of COIL. Dependencies of the threshold singlet oxygen yield and gain coefficient on the relative population of vibrationally excited oxygen are studied.