Linear and nonlinear optical absorption characterization of natural laccaic acid dye

摘要

We report on the optical performances of laccaic acid dye in solution at different concentrations and dye-poly(methyl methacrylate) composite thin films. The linear spectral characteristics including optical constants, i.e. refractive index (n) and extinction coefficient (k), were carried out in a comprehensive way through absorbance, fluorescence and ellipsometric studies. The nonlinear optical parameters such as nonlinear absorption coefficient beta (eff) (or beta (2)), the imaginary third-order susceptibility (Im[chi ((3))]) and the imaginary part of second-order hyperpolarizability (gamma) of the samples were evaluated using the open-aperture Z-scan technique with a laser pulse duration of 10 ns at 532 nm wavelength. The corresponding numerical values of these parameters were of 10(-10), 10(-11) and 10(-32) order, respectively. Two-photon absorption was revealed to be the main driving physical mechanism in the nonlinear response. This suggests that laccaic acid dye can be a potential candidate for NLO materials application.