Detection of vibrationally-excited O 2 in COIL active medium

The vibrationally excited oxygen in O2(a 1Δg)-I mixture was detected by emission spectroscopy. The analysis of a luminescence spectra of oxygen molecules on O2(b 1Σg+,υ') → O2(X3Σg-,υ") transitions has shown, that vibrationally excited O2(b 1Σg+) molecules up to υ=5 are generated in the active medium of chemical oxygen-iodine laser (COIL). The highest values of relative O2(b 1Σg+,υ=1) population of 22% and O2(b 1Σg+,υ=2) of 10% are reached for I2 content in an oxygen flow ≈1%. It is shown theoretically, that the relative populations of O2(X3Σg-), O2(a 1Δg) and O2(b 1Σg+) molecules at the first and the second vibrational levels are approximately equal because of fast EE energy exchange between oxygen molecules. Up to 20% of oxygen molecules in COIL active medium are vibrationally excited.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.