Nonlinear Optical Response of a Polymer Electret with Incorporated Organic Chromophores

An analytical approach aimed at modeling the nonlinear optical (NLO) response of a polymer electret with incorporated organic dipole chromophores is extended to the dynamic case. The approach allows the effect of the locally anisotropic, polarizable, deformable polymer matrix on the chromophore NLO response to be accounted for. The method exploits the original cavity ansatz according to which the virtual cavity occupied by the chromophore in the polymer matrix is chosen to be conformal to the characteristic ellipsoid of the generalized permittivity tensor. Analytical expressions for the dynamic electric moments of dipole chromophores and macroscopic polarization of a polymer electret at fundamental and second harmonic frequencies are obtained by using a computational scheme based on two self-consistency procedures. On the basis of the expressions for dynamic macroscopic polarization, the analytical formulas for linear, chi(i(1))(j) (omega), and quadratic, chi(i(2))(ik) (2 omega), electric susceptibilities are obtained. The presented expressions establish the relationship between the molecular polarizabilities of chromophores and the macroscopic electrical properties of the polymer electret.