Preparation, characterization, and study of the nonlinear optical properties of a new prepared nanoparticles copolymer

Abstract

The nonlinear optical properties of a nanoparticle polyaniline/polyacrylonitrile (PAn/PANr) copolymer newly prepared via experimental and theoretical findings are reported. Diffraction ring patterns result in the far field when a CW, visible, 473 nm, low power laser beam traverses the solution of PAn/PANr in the solvent ethanol. The diffraction ring patterns are usually used to estimate the nonlinear refractive index while the Z-scan is used to measure both nonlinear refractive index and its sign and nonlinear absorption coefficient. The experimentally observed ring patterns are numerically reproduced via the use of the Fresnel–Kirchhoff procedure. Good agreement between experimental findings and the numerical ones are obtained. The obtained diffraction ring patterns suffer modification in the vertical direction due to convection current as a result of local heating of the sample and the presence of gravity.