| The last two decades of research in the field of organic 2nd-order nonlinear optical (electro-optic) materials has led to a deeper understanding of salient fundamental processes. Detailed definitions of critical structure-property relationships have led to the realization of new materials displaying dramatically enhanced properties. Despite the many recent advances, some critical problems remain unsolved. Although molecular nonlinearities (beta) have increased dramatically, bulk nonlinearity values (r33) have not increased in proportion. The major impediment to the resolution of this shortcoming is the difficulty faced in overcoming limited electric field induced molecular ordering caused by inter-molecular electrostatic interactions. Through the use of sophisticated statistical and quantum mechanical modeling, materials were designed which circumvented such detrimental molecular interactions. In the case of chromophore doped multichromophore dendrimers, these interactions were actually harnessed to enhance electric field induced dipolar order. As a result of this rational, theory guided design approach to novel electro-optic materials, unprecedented r33 (>300 pm/V) was demonstrated. Design, synthesis, and detailed characterization of these new materials is presented within this dissertation. Fundamental research toward molecular structure engineering as well as a new approach to optimization of molecular hyperpolarizability is presented as well. |
