Identification of the nonlinear optical properties for a mixture of Sudan yellow 3G and poly methyl methacrylate for optical limiting applications

Abstract

A mixture of sudan yellow 3G dye and poly methyl methacrylate film is fabricated by casting. The optical constants are determined using measurements of absorbance, transmittance, and reflectance spectra. The indirect optical band gap is obtained from Tauc's formula, which is found to be 2 eV. By excitation of the sample with a continuous wave laser beam, the nonlinear optical and the optical limiting properties are studied. The change in refractive index, Δn, and nonlinear refractive index, n2, for the sample is calculated from the diffraction ring patterns and is found to be 44.10 × 10−3 and 18.29 × 10−6 cm2/W respectively. We employ Z-scan to determine nonlinear refractive index n2 = 0.6 × 10−6 cm2/W and nonlinear absorption coefficient β = 8.79 × 10−3 cm/W. The sample is proven to possess the properties of an optical limiter, as the threshold limiting value of the film is equal to 5.3 mW.