Further studies on thermal aspects of inclusion-dominated processes in laser-induced thin film damage

The inclusion dominated model of laser-induced damage is reexamined in order to explore the consequences of recent measured low values of thin film thermal conductivities. In the model absorption of radiation is assumed to only occur in the inclusion via Mie scattering. From the analysis two different values of the imaginary part of the index of refraction are predicted for a given damage threshold. Physical mechanisms are proposed for each value. Interestingly, varying the thermal conductivity of the both the host and inclusion over several orders of magnitude seem to have a less than expected influence on the damage threshold. However there is also proposed an effect of the index of refraction associated with a given damage threshold which is based upon two distinct absorption mechanisms. The results of this modified model are then compared with experimental data for damage thresholds of different thickness films.