Two-dimensional poling of organic and polymer films for improved nonlinear-optical properties

Nematic films doped with molecules of high nonlinear polarizability can exhibit two-dimensional asymmetry after electric-field poling along one direction only. Consequently, these films exhibit more nonzero components of the second-order susceptibility tensor than are obtained through usual poling techniques. These films can exhibit very high nonlinear optical coefficients (close to 10(-7) esu/cm(3)) and retain most of their nonlinearity one week after removal of the poling field.