Formation and Properties of Laser-Induced Periodic Surface Structures on Different Glasses.

Stephan Gräf,Frank Müller,Clemens Kunz

doi:10.3390/ma10080933

Abstract

The formation and properties of laser-induced periodic surface structures (LIPSS) was investigated on different technically relevant glasses including fused silica, borosilicate glass, and soda-lime-silicate glass under irradiation of fs-laser pulses characterized by a pulse duration τ = 300 fs and a laser wavelength λ = 1025 nm. For this purpose, LIPSS were fabricated in an air environment at normal incidence with different laser peak fluence, pulse number, and repetition frequency. The generated structures were characterized by using optical microscopy, scanning electron microscopy, focused ion beam preparation and Fast-Fourier transformation. The results reveal the formation of LIPSS on all investigated glasses. LIPSS formation on soda-lime-silicate glass is determined by remarkable melt-formation as an intra-pulse effect. Differences between the different glasses concerning the appearing structures, their spatial period and their morphology were discussed based on the non-linear absorption behavior and the temperature-dependent viscosity. The findings facilitate the fabrication of tailored LIPSS-based surface structures on different technically relevant glasses that could be of particular interest for various applications.

Highlights

The glasses are the material of choice for numerous high-tech applications including e.g., optics, solar cells, microfluidics, and biomaterials
In the case of fused silica, the lowest fluence value, F = 5.0 J/cm2 leads to the formation of high-spatial frequency LIPSS (HSFL) (Figure 1a) with an orientation perpendicular to the direction of the electrical field (E-field) vector of the fs-laser radiation
Laser-induced periodic surface structures have been prepared on fused silica, soda-lime-silicate glass, and borosilicate glass by using fs-laser pulses

Summary

Introduction

The glasses are the material of choice for numerous high-tech applications including e.g., optics, solar cells, microfluidics, and biomaterials. An important aspect of these glasses is related to their surface-specific properties including absorption, reflection, and wettability that can be tailored by engineering the surface. LSFL often show spatial periods close to the utilized laser wavelength λ or close to λ/n, with n being the refractive index of the dielectric material. It is generally accepted that their formation mechanism is related to a spatially modulated energy deposition pattern resulting from the interference of the incident laser radiation with excited surface electromagnetic waves, which may involve the excitation of surface plasmon polaritons [8]. HSFL with periods much smaller than λ are predominantly observed for the irradiation with pulses in the ps- to fs-range mainly for below

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Conclusion