Nonlinear-optical and fluorescent properties of Ag aqueous colloid prepared by silver nitrate reduction

Abstract

The nonlinear-optical properties of metal Ag colloidal solutions, which were prepared by the reduction of silver nitrate, were investigated using Z-scan method. Under picosecond 532nm excitation, the Ag colloidal solution exhibited negative nonlinear refractive index (n 2 =-5.17 10 -4 cm2/W) and reverse saturable absorption coefficient (β=4.32 cm/GW). The data fitting result of optical limiting (OL) response of metal Ag colloidal solution indicated that the nonlinear absorption was attributed to two-photon absorption effect at 532nm. Moreover, the fluorescence emission spectra of Ag colloidal solution were recorded under excitations at both 280nm and 350nm. Two fluorescence peaks, 336nm and 543nm for 280nm excitation, while 544nm and 694nm for 350nm excitation, were observed. Copyright © 2010 Xiaoqiang Zhang, et al.