Enhanced electro-optic response of layered composite materials

We have constructed a multilayered composite material consisting of alterna ting layers of rf-sputtered barium titanate and spin-coated polycarbonate c ontaining a third-order nonlinear optical organic dopant. The effective non linear susceptibility of the composite describing the quadratic electro-opt ic effect was measured to have the value chi((3)) = (3.2 + 0.2i) x 10(-21) +/- 25% (m/V)(2). The real part of this value is a factor of 3.2 +/- 50% ti mes larger than that of the doped polycarbonate, which is the dominant elec tro-optic component of the composite. We have modeled the experiment by usi ng both effective medium theory and by solving the wave equation for our mu ltilayered system, and we find that these approaches give consistent predic tions which are in good agreement to the experimental results. (C) 1999 Ame rican Institute of Physics. [S0003-6951(99)03117-4].