Synthesis, Linear and Nonlinear Optical Properties of Ag/Al₂O₃ Nanocomposites

This work reports a detailed study of the synthesis, characterization and third-order nonlinear optical properties of Ag and Al₂O₃ nanoparticles and their polymer nanocomposites. Ag and Al₂O₃ nanoparticles were prepared by the chemical precipitation method. The X-ray diffraction studies confirmed the purity and the crystalline nature of the sample and revealed the crystallite size. The linear optical properties and the structural morphology of the nanoparticles were confirmed using UV-visible spectroscopy and SEM analysis. The prepared nanoparticles were introduced into the polymer matrix by the spin-coating technique. Open-aperture and closed-aperture Z-scan technique was used to study the nonlinear absorption and nonlinear refraction of the samples under a Q-switched Nd:YAG laser at 532 nm. The observed third-order nonlinear optical susceptibility (χ⁽³⁾) was on the order of 10^-6 esu, which indicates that these materials are potential candidates for photonic applications.