Influence of diffraction by bulk defects on the damage of end surfaces of ruby crystals

It was found experimentally that the first Fresnel diffraction maximum produced by the edges of a bulk defect, located at a distance of 8–10 mm from the end of a ruby crystal, caused damage of the end surface. This damage was produced by repeated illumination with giant pulses of 0.2 J energy and 30–70 nsec duration.