Investigation of Self-Induced Thermal Effects of CO2 Laser Radiation Propagating in Absorbing Gases

The report summarizes the work performed during the second year of an experimental and theoretical research program concerning the self-induced thermal distortion effects on cw CO2 laser radiation propagating in absorbing media. The research program is directed toward improving the understanding of the possible limitations imposed by the atmosphere on the propagation of high power laser radiation. The work presented is concerned with essentially the following three different areas: (1) wind simulation experiments using a high pressure gas cell; (2) studies of the kinetic cooling of a gas by absorbing of CO2 laser radiation; and (3) studies of turbulence effects on the self-induced thermal distortion of laser beams.