Anisotropic reversing motion in laser-induced periodic surface structures

Abstract

Observation of the evolution process of laser-induced periodic surface structure (LIPSS) will provide clues to its formation mechanism. We constructed a pulse-by-pulse image capture setup using oil-immersion optical microscopy with which we observed the evolution process on a coverslip of borosilicate glass, finding three LIPSS patterns: stripe patterns parallel and perpendicular to the electric field of the laser pulse, and a dot pattern. Furthermore, “reversing” motion was observed, that is, bright and dark interchange from pulse to pulse. The reversing motion had remarkable anisotropy, moving only perpendicular to the electric field of the laser pulse.