Dynamics of deformations outside a laser-induced cylindrical focal zone: analytical solutions

This paper analytically describes the dynamics of deformations occurring outside a cylindrical laser-induced focal zone during laser microstructuring of glass-forming materials. Problems associated with high and moderate laser pulse intensities are considered. In both cases, significant stresses arise outside the focal zone at distances significantly exceeding its size, as well as stress anisotropy of the order of 1 GPa. Such stresses can irreversibly change the material outside the focal zone. Thus, if the elastic limit of the material is known, it is possible to predict the conditions under which the material can be irreversibly deformed at various distances outside the focal zone. Such deformations outside the focal zone can limit the accuracy of the created microstructures, which is of interest, in particular, for optical data storage systems and fiber-optic integrated circuits (in particular, for waveguide splitters and connectors). In fact, analytical solutions provide detailed information on the dynamics of stress and strain fields outside the focal zone, which is often difficult to obtain experimentally. This knowledge can be useful for better understanding and development of technologies related to laser microstructuring.