Hyper-Rayleigh scattering in solution.

Hyper-Rayleigh scattering in solution is used for the determination of the hyperpolarizability of nonlinear optical molecules. Obtaining the first hyperpolarizability \ensuremath{\beta} without having to independently determine the dipole moment \ensuremath{\mu} and the second hyperpolarizability \ensuremath{\gamma} is an advantage over the electric-field-induced second-harmonic generation technique. Values of the first hyperpolarizability \ensuremath{\beta} of 23\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}30}$ esu for para-nitroaniline, 105\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}30}$ esu for 4-methoxy-4'-nitrostilbene, and 95\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}30}$ esu for 4-hydroxy-4'-nitrostilbene dissolved in chloroform have been obtained. The equivalent-internal-field model is shown to hold for small saturated molecules.