Development of periodically concentric rings within microcavity upon femtosecond laser irradiation

Opt Express. 2023 May 22;31(11):17836-17847. doi: 10.1364/OE.486531.

Abstract

Understanding the formation mechanisms of the nanostructures and their designs has important implications for both the fundamental science and application prospects. In this study, we proposed a strategy for femtosecond laser-induced high regularity concentric rings within silicon microcavity. The morphology of the concentric rings can be flexibly modulated by the pre-fabricated structures and the laser parameters. The physics involved is deeply explored by the Finite-Difference-Time-Domain simulations, which reveals that the formation mechanism can be attributed to the near-field interference of the incident laser and the scattering light from the pre-fabricated structures. Our results provide a new method for creating the designable periodic surface structures.