ROLE OF ABSORBING MICROINCLUSIONS IN THE MECHANISM OF LASER BREAKDOWN OF WIDE-ZONE DIELECTRICS.

The contribution of metallized microinclusions in the volume of a transparent dielectric to the mechanism of laser failure of the material is examined. It is shown that in dielectrics with a wide forbidden zone, an electrostatic breakdown of the dielectric takes place in the vicinity of the inclusion in the radiation field. During this breakdown, the inclusion becomes a source of electron-hole plasma which causes the extensive absorption of radiation in the vicinity of the inclusion and leads to failure of the dielectric. Threshold equations are derived for the intensity of radiation above which the material fails in the presence of inclusions of a specific radius.