Z-scan determination of the third-order optical nonlinearity of organic dye nile blue chloride

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 chi((3)) being -4.12 x 10(-5) esu and 1.35 x 10(-6) esu, respectively. These results show that the Nile Blue chloride dye has potential applications in nonlinear optics.