Third order nonlinear optical properties of gold/alumina multilayer nanocomposites with different nanoparticle arrangements

Abstract

The linear and nonlinear optical properties of gold nanoparticle/alumina matrix multilayer nanocomposites obtained by successive laser deposition were studied. The nonlinear optical properties of the gold nanoparticle layers embedded in alumina were determined by Z-scan at 532 nm, using a picosecond pulse laser. The linear absorption, third-order nonlinear absorption and refraction were found to depend on the arrangement of gold nanoparticles in the nanocomposite thin film, when essential characteristics such as nanoparticle dimension, metal concentration and total film thickness are constant. When partial self-correlation between gold nanoparticles in successive layers occurs, in the case of thin alumina layers, linear and nonlinear optical properties of the nanocomposites are enhanced, reaching values of -2.8 × 10−6 m/W and 1.6 × 10−13 m2/W for the third-order nonlinear absorption and refraction coefficients, respectively.