Study of self-defocusing, reverse saturable absorption and photoluminescence in anthraquinone PMMA nanocomposite film.

The nanocomposite film of 1,5-diamino-9,10-anthraquinone in poly methyl methacrylate has been fabricated by following guest-host method. Intense reverse saturable absorption and self-defocusing effect have been investigated by employing Z-scan technique with low power CW laser at 532 nm with different intensities for the dye-polymer composite film. The estimated values of nonlinear absorption coefficient β, nonlinear refractive index n2 and third order susceptibility χ((3)) of the composite film are of the order of 10(-3) (m/W), 10(-11) (m(2)/W) and 10(-4) (esu), respectively. The dye molecules have been encapsulated uniformly between molecules of polymer as a nanocomposite with average roughness ∼7.96 nm as characterized by AFM technique. The nanocomposite film also exhibited strong photoluminescence emission when excited with 532 nm. The second order hyperpolarizability of composite film has also been estimated. The evaluated figure of merit W having a value greater than 1, and the results obtained suggest that the composite film of 1,5-diamino-9,10-anthraquinone-PMMA has potential applications in nonlinear optical devices.