Role of vibrationally excited O2(1Δ) in COIL

The analysis of a luminescence spectra of oxygen molecules on O2(b1Σg,υ’)→O2(X3Σg-υ") transitions has shown, that vibrationally excited O2(b1Σg+) molecules up to υ=5 are generated in the active medium of chemical oxygen-iodine laser (COIL). Comparison of experimental and calculated results has shown that 4.5 vibrational quanta of oxygen are formed in the active medium of COIL under the deactivation of one singlet oxygen molecule. Dependencies of the threshold of O2(α1Δg) yield and gain on relative population of vibrationally excited oxygen are studied. The threshold of O2(α1Δg) yield increases with rising of the relative population of vibrationally excited oxygen and can be some percents more than it was considered before. The gain coefficient weakly depends on the relative population of vibrationally excited oxygen.