How Light Drives Material Periodic Patterns Down to the Nanoscale

Abstract

Ultrashort laser pulses enable efficient energy confinement down to the nanoscale, inducing extreme thermodynamic conditions in condensed matter. In contrast to longer pulse excitation, high-energy gradients are established, able to trigger nonlinear phenomena and instabilities that result from multiphysics coupling from the atomic to the macroscale. Self-organization of matter into periodic nanoscale patterns under multipulse laser excitation is one of the most intriguing manifestations of these phenomena with a wide range of potential applications in optics and mechanics, and of a fundamental scientific interest. This chapter provides an overview of the relevant processes with a particular emphasis on material modifications occurring in dielectrics, semiconductors, or metals and a critical assessment and discussion of plausible scenarios of matter reorganization toward periodic nanoscale patterns. Relying on representative experimental observations, proposed explanations are supported by numerical simulations. The dynamic interplay between light and matter evolution is explored to pave the way for structuring self-arranged surfaces on dimensions well below the diffraction limit and reaching the sub-100-nm feature size. Open questions and unexplored directions of possible further research work are outlined along the lines of the chapter.