2022 · OPTICS EXPRESS

High-fidelity glass micro-axicons fabricated by laser-assisted wet etching

Skora, Jean-Loup, Gaiffe, Olivier, Bargiel, Sylwester, Cote, Jean-Marc, Tavernier, Laurent, de Labachelerie, Michel, Passilly, Nicolas

Journal
OPTICS EXPRESS
Année
2022
Volume
30
Numéro
3
Pages
3749-3759
Mois
JAN 31
DOI
10.1364/OE.446740

Abstract

We report on the fabrication of micro-axicons made of glass by laser-assisted wet etching (LAE) and laser polishing. The employed technique, relying on a direct-writing process using a femtosecond laser, allows revealing high fidelity profiles when the exposed glass samples are etched in a heated potassium hydroxide (KOH) solution. The remaining surface roughness is then decreased by carbon dioxide (CO2) laser polishing. Such polishing is limited to the superficial layer of the component so that the tip is only slightly rounded, with a radius of curvature of nearly 200 mu m. It is then shown with 500 mu m-diameter axicons that a quasi-Bessel beam is generated closely after the tip and features a 5.3 mu m diameter maintained over a propagation distance of almost 3.5 mm. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Lire l'article complet