Photochemical processes in atmospheric gases and nonlinear refraction of gaseous xenon by means of excimer lasers

Studies of primary mechanism of ozone formation in oxygen- containing mixtures and nonlinear refraction of gaseous xenon under the action of excimer laser radiation are reported. The dependence of ozone formation rate in compressed oxygen and in xenon-oxygen mixture on gas pressure and temperature was measured simultaneously with absorption measurements in the Herzberg band at two wavelengths of exciting radiation (248 and 224 nm). Analysis of experimental data shows that the primary mechanism of ozone formation under the action of KrF laser radiation is conditioned by the absorption of an oxygen molecule from the ground vibrational state in the Herzberg band with subsequent collisional dissociation of the excited molecule. The nonlinear contribution to the refractive index of high- pressure xenon at room temperature at the wavelength of XeCl laser radiation was measured with the help of the Twyman interferometer. Using the dependence of the shift of an interference pattern on the light intensity, the sign and the magnitude of the nonlinear contribution are obtained, which gave (Delta) n/ equals -6(DOT)10-12 electrostatic CGS unit. This value is shown to be determined by the balance of electrostrictional and electrocaloric mechanisms; it exceeds the electronic contribution to nonlinear refraction by two orders of magnitude.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.