Investigation of optical components under irradiation with high-power, cw CO2 lasers

Optical components used in high-power, cw-lasers must withstand power densities of up to several tens of kW/cm (exp 2) over long periods of time without appreciable changes in their properties (BERGER & REEDY, GUENTHER). Most important for applications in resonator cavities and in beam guiding and delivery systems are such characteristics as optical absorptivity, thermal conductivity and capacity, chemical stability, and surface morphology. Changes induced in one of these by high-power laser radiation might also affect the others, resulting in a relatively complex physical process, possibly leading to long-term degradation or catastrophic failure of the components. A basic understanding of such processes and the connection to damage is a goal of the present work