Realization of sub 1 V polymeric EO modulators through systematic definition of material structure/function relationships

Quantum mechanics and new statistical mechanical methods have been employed to optimize macroscopic electro-optic activity for organic chromophore-containing polymeric materials. In particular, statistical mechanical (equilibrium and kinetic Monte Carlo) methods that explicitly take into account many-body, spatially-anisotropic, intermolecular interactions are necessary to understand the variation of macroscopic electro-optic activity with chromophore number density, shape, dipole moment, polarizability, and polymer dielectric constant. With guidance from theory, materials have been prepared that exhibit electro-optic coefficients of greater than 100 pm/V. Halfwave voltages of less than one volt have been realized for devices fabricated from these materials. Low halfwave voltage, ultrahigh bandwidth, and ease of incorporation into sophisticated 3-D circuits are some of the demonstrated advantages of polymeric electro-optic devices; however, for such devices to be commercially viable they must exhibit exceptional stability in harsh environments (high temperature and optical power exposure). Lattice hardening (intermolecular cross-linking plays a critical role in defining chemical, photochemical, and thermal stability. Optical insertion loss is another issue that requires attention to both material design and device structure. Techniques for reducing insertion loss are cited. New material performance capabilities have led to new device concepts and demonstrations; several examples are given. (C) 2001 Elsevier Science B.V. All rights reserved.