Improvement of Etching Anisotropy in Fused Silica by Double-Pulse Fabrication

Autor: Valdemar Stankevič, Jonas Karosas, Gediminas Račiukaitis, Paulius Gečys
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Micromachines, Vol 11, Iss 5, p 483 (2020)
Druh dokumentu: article
ISSN: 2072-666X
DOI: 10.3390/mi11050483
Popis: Femtosecond laser-induced selective etching (FLISE) is a promising technology for fabrication of a wide range of optical, mechanical and microfluidic devices. Various etching conditions, together with significant process optimisations, have already been demonstrated. However, the FLISE technology still faces severe limitations for a wide range of applications due to limited processing speed and polarization-dependent etching. In this article, we report our novel results on the double-pulse processing approach on the improvement of chemical etching anisotropy and >30% faster processing speed in fused silica. The effects of pulse delay and pulse duration were investigated for further understanding of the relations between nanograting formation and etching. The internal sub-surface modifications were recorded with double cross-polarised pulses of a femtosecond laser, and a new nanograting morphology (grid-like) was demonstrated by precisely adjusting the processing parameters in a narrow processing window. It was suggested that this grid-like morphology impacts the etching anisotropy, which could be improved by varying the delay between two orthogonally polarized laser pulses.
Databáze: Directory of Open Access Journals