Influence of structure defects on the damage threshold of ZnSe crystals

Optical breakdown in the bulk of ZnSe subjected to τ ~100 nsec pulses of λ = 10.6 μ laser radiation resulted from thermoelastic damage of submicron gas–selenium particles containing radiation-absorbing associates of carbon with oxygen and hydrogen. The breakdown power density was governed not so much by the density of the particles as the nature of defects which they decorated. The proposed grading of the defect content of crystals should make it possible to estimate the bulk optical strength of zinc selenide without destructive testing.