4. Influence of irradiation parameters on laser flux behaviour, scaling laws

Irradiation parameters, such as wavelength, beam size and pulse duration, have a significant influence on the laser flux resistance of an optical component. Operating conditions, particularly laser irradiation parameters, may differ from those of the optics' flux withstand specification. This is generally the case for a component purchased from a supplier, for which a flux resistance value is given. In this case, it is essential to know the influence of irradiation parameters on laser flux resistance, and the various existing scaling laws, in order to relate the given value to actual conditions of use.

We describe below how these parameters can affect resistance to laser radiation, and the scaling laws that can be used to estimate their effects. While these elements make it possible to estimate operating conditions with a safety margin, the current state of research...