Surface plasmon-enhanced third-order optical non-linearity of silver triangular nanoplate

We have obtained Ag triangular nanoplates with plasmon resonance bands locating from 750 to 950 nm by wet chemical method. The third-order optical non-linear response property of Ag triangular nanoplate is investigated using z-scan technique. The incident wavelength dependence of χ(3) (the third-order susceptibility) shows the third-order nonlinear behaviour of Ag nanoplate is greatly modified by its plasmon resonance property, for the largest value of χ(3) is observed around the wavelength of plasmon resonant peak. Also, we find the maximum value of Ag nanoplate’s χ(3) is 7.46 × 10−11 esu, which is about 1–3 orders of magnitude larger than that of many other nanomaterials including Au nanorod, nanobipyramid and nanocube, as well as Ag nanosphere and nanodisc. This fact indicates the Ag triangular nanoplate is a kind of useful nonlinear material with larger third-order nonlinearity, showing great potentials in the explorations of functional non-linear devices.