On the formation of periodic structures on solid surfaces

Abstract

A model is proposed to explain the formation of periodic structures produced on solid surfaces by laser radiation. The model gives rise to a system of two linear integrodifferential equations with difference kernels for temperature correction due to the specific absorption of electromagnetic energy at a certain solid surface profile and at a surface profile formed due to heat expansion resulting from temperature correction. The solution of this system reveals, that, first, periodic structures are formed as a result of the propagation of “periodic” profiles generated from a certain original non-periodic profile over the body surface. Second, the amplitudes of these waves grow with time only for a laser density exceeding certain critical value, i.e. the formation of periodic structures is a threshold effect relative to the laser density.