Modelling optical polarization processes on laser modified titanium with a polyvinyl alcohol film

Abstract

The article presents the results of research of optical spectra of surface plasmon polaritons on laser modified titanium with a deposited micron polymer polyvinyl alcohol (PVA) film. The metasurface of titanium was created by means of femtosecond laser treatment with l = 1.035 µ and the duration t = 280 fs with linear and circular radiation polarization. Sets of laser pulses were applied pointwise to the surface with a step of 100 μm with the interval ti = 25–750 ms. In the case of linear radiation polarization, tracks of ripple structures with a line density of up to N ~ 1,200 mm–1 appeared on the scribed titanium surface. It was found that when titanium is exposed to circular polarization radiation, occasional ablation cavities with lobed circular ripple nano-microstructures appear along the line of beam pulse propagation. Mathematical modelling of real Re(e) and imaginary Im(e) permittivity established that the spectral parameters in the reflectance spectra of polarized radiation almost fully matched. The analysis of the spectra also established that the maximum absorption was in the IR region due to the presence of a PVA film.

Keywords

• plasmon resonance
• laser structuring
• circular polarisation
• metasurface
• pva film