Second-Order Nonlinear Optical Properties Of Thiophene Containing Chromophores With Extended Conjugation

The synthesis and first hyperpolarizabilities (β) of various donor-acceptor substituted thiophene containing compounds with extended conjugation are reported. Results indicate that replacing phenyl rings with less aromatic thiophene moieties enhances the second-order hyperpolarizability. Incorporating the acceptor group, N,N’ diethylthiobarbituric acid, that can gain aromaticity upon charge-separation has also led to an increase in the nonlinearity. Some of the molecules have been incorporated into poIy(methyl methacrylate) and the electro-optic coefficients of these host-guest polymers were measured.