مشخصات پژوهش

This study synthesised nanocomposites by incorporating selenium nanoparticles into polymeric materials, specifically polyethylene oxide (PEO), polyvinyl alcohol (PVA), and poly(methyl methacrylate) (PMMA). The investigation focused on their linear, nonlinear, structural, and formal optical properties. The properties of nanocomposites can be enhanced by incorporating them into polymeric materials appropriate for various applications. Nanocomposites are significant in nonlinear optics (NLO) owing to their substantial nonlinear response and broad spectral transparency. The three nanocomposites, Se+PEO, Se+PVA and Se+PMMA, were prepared and characterised through XRD, FESEM, EDX, FTIR, RSS, and PL techniques. The linear optical properties of the prepared samples were analysed using UV-VIS spectroscopy at various concentrations achieved through the addition of different polymers. The results indicated that an increase in concentration corresponded with a rise in absorbance at the same wavelength, with Se+PMMA exhibiting a higher absorbance compared to the other compounds. The fluorescence of all prepared samples was measured, and the results indicated that an increase in concentration led to a decrease in fluorescence. The Z-Scan technique, encompassing both open and closed aperture measurements, was employed to determine the nonlinear refractive index (n2) and the nonlinear absorption coefficient (β). The experiment utilised a solid-state diode laser operating at a wavelength of 405 nm and a power output of 2.94 mW. The Se+PMMA composite exhibits superior nonlinear behaviour compared to the other nanocomposites.