Temperature Measurement in a CO2 Laser Beam by Laser-Induced Fluorescence of O2

Abstract

A mixture of SF6-O2 is irradiated by an infrared (10.6 μm) cw CO2 laser. Absorption by SF6, and subsequent collisional energy transfer, heats the mixture. Vibrationally excited ground-state O2 is detected at levels v = 0, 1, and 2 by laser-induced fluorescence in the B3 Σu− X3Σ8− – Schumann-Runge system with an ArF laser (193.3 nm). Comparison of the observed LIF spectrum with spectra simulated at various temperatures shows that the molecular oxygen in the IR laser beam is thermalized at a temperature of about 700 K.