Nonlinear optical susceptibility measurements of solutions using third-harmonic generation on the interface

By simultaneous measurements of the third-harmonic intensity on two interfaces, it is possible to make precise and fast measurements of the third-order nonlinear optical susceptibility of solutions. We propose a simple nonlinear optical technique that eliminates the effects of both scattering and absorption, thus allowing for characterization of colloidal solutions with possible aggregation. The proposed technique is experimentally demonstrated for a variety of solutions, both transparent and scattering, and shows very good agreement with data obtained by other means. (C) 2003 American Institute of Physics.