Measure of surface defectiveness and optical strength of transparent dielectrics

Absorbing inclusions were introduced deliberately in a study of the influence of surface defects in transparent dielectrics on their optical strength. It was found that the surface strength was governed mainly not by its relief but by the presence of a defective surface layer. It was established that the measure of surface defectiveness, defined as the ratio of the bulk to the surface strength, was less than unity for plastic materials and more than unity for brittle materials.