Author : Hammad R.Humud*, Manal Midhat Abdullah and Dawood Majed Khudhair

In this work, the nonlinear optical properties of pure polyaniline and in situ iodine doping polyaniline thin films on glass substrate, prepared by aerosol assisted plasma jet polymerization at atmospheric pressure, thin films were studied through open and closed Z-scan technique under laser excitation at 532 nm, CW solid state laser with an output power of 100 mW. The nonlinear optical properties of pure polyaniline thin films prepped at different gas flow rate and polyaniline thin films iodine doped at constant gas flow rate 1lm-1 and different iodine weight concentration 1, 3, 5, and 7%were studied. the closed aperture Z-scan data indicates that the sign of the refraction nonlinearity is negative for thin films prepared at gas flow rate 1lm-1, n2 1.965×10-5 cm2/mw .and positive nonlinearity for thin films prepared at other gas flow rate,n2 1.207×10-5, 1.076×10-5 and 1.214×10-5 cm2/mw for gas flow rate 2,3 and 5 lm-1 respectively. And the open Z-scan measurements show two photon absorption β cm/mW, 1.40, 1.16, 1.12 and 1.37cm/mW for gas flow rate1, 2, 3 and 5 lm-1respectively. For polyaniline thin films iodine doped at constant gas flow rate the closed aperture Z-scan measurements shows positive nonlinearity for thin films prepared at iodine concentration 3 and 5% n2 1.606×10-5, 0.830×10-5 cm2/mw respectively. While thin films prepared with iodine concentration 1 and 7% shows negative nonlinearity n2 0.857×10-5, 0.801×10-5 cm2/mW respectively. The open aperture Z-scan measurements for polyaniline thin films doped with iodine by different concentration 1, 3, 5, and 7% and constant gas flow rate show saturated absorption for all gas flow rate. It can be concluding that, the possibility of obtaining direct and inexpensive method to prepare saturated absorption thin films material, by aerosol assisted plasma jet polymerization at atmospheric pressure.

Keywords: Polyaniline iodine doping, thin films, nonlinear optical properties.

Article published in International Journal of Current Engineering and Technology, Vol.5, No.5 (Oct-2015)