Guest−Host Cooperativity in Organic Materials Greatly Enhances the Nonlinear Optical Response

Some of the most highly active organic electro-optic (EO) materials developed recently rely on the combination of an EO-active (chromophore-containing) host material (dendrimer or side-chain polymer) and an EO-active (chromophore) guest. These new binary-chromophore materials exhibit EO coefficients (r 33) in the range of 250 to greater than 300 pm/V (currently as high as 450 pm/V). The EO activity of these binary-chromophore materials is greater the sum of their individual components. The experimentally observed increase in the nonlinear optical response of two representative classes of EO chromophore−EO dendrimer and EO chromophore−EO polymer mixtures relative to the response of the isolated components is described quantitatively herein by a physical model that accounts for cooperativity in the guest−host interactions.