Mean-field theory of acentric order of dipolar chromophores in polymeric electro-optic materials

A mean-field theory of macroscopic order of dipolar chromophores in a polymer matrix in the presence of an external electric field is developed. The theory is applied to characterize the electro-optic coefficient of the Pockel effect that forms the basis for a variety of polymeric nonlinear electro-optic materials. The coefficient is studied as a function of chromophore concentration, polymer properties, and manufacturing conditions, including temperature, strength of the applied electric field, and macroscopic shape of the sample. The model reproduces the observed behavior of the electro-optic coefficient and explains the nonlinear concentration dependence of the coefficient at high chromophore concentrations. Specific recommendations for system design are suggested from the analysis of the obtained data.