Evolution of femtosecond laser damage in a hafnia-silica multi-layer dielectric coating

0522224 - FZÚ 2020 RIV US eng J - Článek v odborném periodiku
Velpula, Praveen K. - Ďurák, Michal - Kramer, Daniel - Meadows, A.R. - Vilémová, Monika - Rus, Bedřich
Evolution of femtosecond laser damage in a hafnia-silica multi-layer dielectric coating.
Optics Letters. Roč. 44, č. 21 (2019), s. 5342-5345. ISSN 0146-9592. E-ISSN 1539-4794
Grant CEP: GA MŠMT EF15_008/0000162; GA MŠMT ED1.1.00/02.0061; GA MŠMT EE.2.3.20.0091; GA MŠMT EF16_019/0000789
Grant ostatní: ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162; ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OP VK 1 LaserSys(XE) CZ.1.07/2.3.00/20.0091; OP VVV - ADONIS(XE) CZ.02.1.01/0.0/0.0/16_019/0000789
Institucionální podpora: RVO:68378271 ; RVO:61389021
Klíčová slova: surface * ablation * laser damage * hafnium oxides * damage morphology
Obor OECD: Optics (including laser optics and quantum optics); Materials engineering (UFP-V)
Impakt faktor: 3.714, rok: 2019
Způsob publikování: Omezený přístup
https://doi.org/10.1364/ol.44.005342

To optimize optical coating materials, designs, and technologies for high damage resistance, understanding the growth of laser damage is of paramount importance. In this Letter, we show the evolution of femtosecond laser damage in a hafnia–silica (HfO2/SiO2) multilayer dielectric mirror coating. Depending on various spatial features of damaged sites, we identified several regimes of the laser–material interaction with varying laser fluence and incident number of pulses. A change in surface roughness has been observed only for a small number of pulses, and interestingly, a threshold number of pulses is found for nanocrack formation. We report the polarization-dependent orientation of nanocracks and their growth with an increasing number of pulses. The presented results demonstrate that the laser damage originates from the nanobumps and surface roughening, which then leads to the formation of nanocracks. The presented experimental results acknowledge the existing theoretical models..
Trvalý link: http://hdl.handle.net/11104/0306744