Estimation of electrostriction coefficients of a nonlinear optical polymer electret

The effect of organic chromophores incorporated into a polymer electret and responsible for its nonlinear optical (NLO) response to an applied electric field on the electrostriction coefficients (ESC) of the material is studied. Analytical expressions for the ESC were derived in the framework of a model proposed earlier, which includes the effect of a locally anisotropic, polarizable and deformable environment on the electric characteristics of the chromophore. The dependence of the ESC on both macroscopic and microscopic parameters of the molecular system is established. Numerical estimates of the ESC for poly(methyl methacrylate) doped with the dye Disperse Red 1 and dimethylaminonitrostilbene-doped polycarbonate agree with experimental data in order of magnitude. The relations obtained can be used in the design of novel organic NLO materials.