Optical limiting performance of silver, gold, and silver–gold nanomaterials.

This study used a chemical reduction technique to create metallic nanomaterials made of silver (AgNPs), gold (AuNPs), and composite silver–gold nanocomposite (Ag–AuNPs). The spherical shape of the obtained AgNPs and AuNPs, with average diameters of approximately 12 nm and 15 nm, respectively, was confirmed by transmission electron microscopy (TEM) examination. AgNPs and AuNPs both showed plasmonic absorption peaks at 405 nm and 525 nm, respectively. Upon the formation of the composite material, the plasmonic absorption peaks remained consistent, indicating both metallic Ag and Au nanoparticles. The nonlinear absorption coefficient β values and signs were determined using an open aperture Z -scan setup. Positive nonlinear absorption coefficients were calculated for AgNPs, AuNPs, and Ag–AuNPs, indicating the materials' potential for effective optical limiting. The Ag–AuNPs exhibited a combination of Ag and Au nanoparticle nonlinearities, further enhancing their suitability as candidates for optical limiting applications. Overall, the well-defined features of the synthesized Ag, Au, and Ag–Au nanocomposites, along with their favorable nonlinear absorption coefficients, highlight their promising prospects as optical limiting materials. [ABSTRACT FROM AUTHOR]