Hyper-Rayleigh scattering studies of first-order hyperpolarizability of squarylium dye in solution

Abstract

We have synthesized a squarylium dye based on 2,6-di-tert-butylpyrylium (full name given in the text). Its nonlinear optical properties was detected by the hyper-Rayleigh light scattering technique in a chloroform solution, although this type of chromophore has a symmetrical structure and a negligible permanent dipole moment. The internal reference method was employed to determine the first hyperpolarizability β value of the chromophore and further discussion is provided.