Plasmon enhanced two-photon absorption in modified Styrene–Maleic Anhydride Silver nanocomposites

Styrene–Maleic Anhydride (SMA), a synthetic copolymer, possess aromatic and anhydride functionalities with interesting thermal and membrane properties. In this work, we report on the nonlinear optical studies in Schiff base modified SMA by open aperture Z-scan experiments with 532 nm, 5 ns laser pulses. In addition, we incorporate Silver nanoparticles in the polymer SMA so as to enhance the nonlinear absorption. The nonlinear absorption coefficient is found to be nearly 0.8×10−11 m/W for the neat polymer. On incorporation of Silver nanoparticles in SMA, the nonlinear absorption coefficient is found to be increasing to 0.1×10−8 m/W, which is nearly three orders higher than SMA. The enhanced nonlinear absorption coefficient in polymer–metal nanocomposites is attributed to local field effects induced by metal nanoparticle. We also observed that the optical limiting threshold of the synthesized polymer nanocomposite can be tailored as a function of Silver nanoparticle concentration. Our observations indicate that the incorporation of metal nanoparticles, with the excitation wavelength non-resonant with the surface plasmon peak, offer a strategy to control the third order nonlinear optical properties of the polymer nanocomposite, making it suitable for various optoelectronic applications.