Formation of cross-superposed LIPSSs on bulk chalcogenide glasses using fs-laser

Abstract

Abstract This paper reports the formation of laser-induced periodic surface structures (LIPSS) observed on the ablated surface of bulk As 2 S 3 chalcogenide glasses produced after irradiation by a focused beam of femtosecond Ti:sapphire (fs)-laser (1 kHz, 100 fs, 800 nm). By controlling the irradiation condition of fs-laser, high spatial frequency LIPSS (HSFL) ripples parallel to polarisation of the incident light are formed. Nanovoids with an average diameter of ~300 nm and depth of 200 nm also appear between the ripples. Furthermore, we show a transition from the HSFL features toward the formation of low-spatial-frequency LIPSS (LSFL) with an intermediated complex structure of ripples, which are oriented simultaneously parallel and perpendicular to the polarisation of the incident light that we call cross-superposed LIPSSs.