Failure mechanism of optically transparent solids subjected to a local thermal laser pulse

Experimental data on the failure mechanism of glass plates subjected to a millisecond pulse of focused laser light are presented. It is established as a result of investigation of the failure kinetics of irradiated glass plates that their failure is caused by an increase in gas pressure in the cavity formed at the focal point of the light-collecting lens. This failure mechanism of glass differs from that described earlier for the case of the irradiation of a glass plate by a nanosecond pulse of laser light, according to which the glass fails as a result of the development of a high-amplitude acoustic pressure wave near the front surface of the irradiated plate. The failure mechanism described for the glass plates agrees with a thermodynamic failure model of transparent solids.Translated from Problemy Prochnosti, No. 4, pp. 88–93, April, 1993.