Z-SCAN DETERMINATION OF THE THIRD-ORDER OPTICAL NONLINEARITY OF ORGANIC DYE NILE BLUE CHLORIDE

Abstract

The single beam Z-scan technique was used to determine the nonlinear optical properties of the organic dye Nile Blue chloride in the solvent ethanol. The experiments were performed with a He-Ne laser with a wavelength of 632.8 nm. The negative nonlinear refractive index and two-photon absorption coefficient were observed in this dye. The intensity-dependent nonlinear refractive index was investigated. The result shows that the dye exhibits a great nonlinear response with the real and imaginary parts of the third-order nonlinear optical susceptibility χ(3) being -4.12×10-5 esu and 1.35×10-6 esu, respectively. These results show that the Nile Blue chloride dye has potential applications in nonlinear optics.