Abstract

A CO₂ TEA oscillator-amplifier system has been used to study the laser damage properties of coatings designed for use In pulsed 10,6-μm laser systems. The damage data for large and small incident beam areas have been studied along with data from nondestructive tests such as Nomarski microscopy and visible laser light scattering. In addition to attempting to find a correlation between the observed damage properties and the discrete defects or scattering sites, one of the objectives of this work was to find a nondestructive means to evaluate a coating's damage resistance. Data are presented that demonstrate a correlation between low damage threshold and the presence of visible laser light scatterers. These results also indicate the potential for a minimum threefold Increase in the single-pulse damage threshold of reflective coatings by eliminating such scatterers.

© 1985 Optical Society of America