Interferencinis paviršių apdirbimas panaudojant femtesokundinius ultravioletinius impulsinius pluoštus /

Tadas Latvys INTERFERENCE SURFACE STRUCTURING USING FEMTOSECOND ULTRAVIOLET PULSED BEAMS Interference patterning with femtosecond ultraviolet (UV) pulsed beams enables rapid, precise, and straightforward surface structuring at micrometer and nanometer scales without the need for additional sample preparation or post-processing. Functional surfaces with anti-reflective, superhydrophobic or antibacterial properties find widespread applications in photonics, electronics, labeling, medicine, and tribology. In this work, interference patterning was performed with the third harmonic of a Yb:KGW femtosecond laser. A Talbot interferometer scheme was used to overlap the beams and achieve an interference pattern on the sample surface. To optimize the interferometer configuration, we applied the Kostenbauder matrix method. Our experiments focused on silicon samples due to their well-known properties and extensive use in photovoltaics. Theoretical modeling guided the choice of the optimal Talbot interferometer configuration: parallel mirrors and a cylindrical lens with an axis perpendicular to the interferometer mirrors. Using this setup, periodic structures were fabricated (704 nm<&#923;<800 nm) on the sample surface using the wavelength of &#955;=343 nm and 240 fs pulses, close to the threshold value for amorphization (F_th=38,42 J/cm2). By adjusting the angle of the interferometer mirrors, we observed structures with smaller periods (&#923;=530 nm), however characterized by reduced dimensions and a higher threshold fluence value. After selecting the surface scanning strategy in such a way that qualitatively observed defects of the connection joints were minimized, a grating of macroscopic dimensions was produced, which was characterized by a modulation depth of 60 nm and a period of &#923;=704 nm.

Grantor dc:publisher

Institutional Repository of Vilnius University

Year dc:date

2024

Author dc:creator

• Latvys, Tadas,

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

lit

Repository record dc:identifier

https://repository.vu.lt/VU:ELABAETD210578499&prefLang=en_US

OAI identifier oai:identifier

oai:vu.lt:elaba:210578499