Nonlinear optical properties of periodic gold nanoparticle arrays

Abstract

Periodic Au nanoparticle arrays were fabricated on silica substrates using nanosphere lithography. The identical single-layer masks were prepared by self-assembly of polystyrene nanospheres with radius R=350nm. The structural characterization of nanosphere masks and periodic particle arrays was investigated by atomic force microscopy. The nonlinear optical properties of the Au nanoparticle arrays were determined using a single beam z-scan method at a wavelength of 532nm with laser duration of 55ps. The results show that periodic Au nanoparticle arrays exhibit a fast third-order nonlinear optical response with the nonlinear refractive index and nonlinear absorption coefficient being n2=6.09×10−6cm2/kW and β=−1.87×10−6m/W, respectively.