Pure Appl. Chem., 2004, Vol. 76, No. 7-8, pp. 1421-1433
Organic electro-optic materials
Abstract: The macroscopic electrooptic activity of organic materials depends upon the molecular hyperpolarizability, beta, of individual organic chromophores and upon the product of number density, N, and noncentrosymmetric order, <cos3theta>, of the chromophores in a hardened polymer lattice. Quantum and statistical mechanical calculations provide the basis for rational improvement of these parameters leading to electro-optic coefficients (at telecommunication wavelengths) of greater than 100 pm/V (a factor of 3 larger than values for the best inorganic material, lithium niobate). Such calculations also provide insight into what further improvements can be expected. Owing to low and relatively dispersionless dielectric constants and refractive indicies, organic materials facilitate the fabrication of devices with 3 dB operational bandwidths of greater than 100 GHz. Moreover, robust and low optical loss materials can be fabricated by design. An under-appreciated advantage of organic electro-optic materials is their processability, and a variety of stripline, cascaded prism and super-prism, and ring microresonator devices are readily fabricated. Conformal, flexible, and three-dimensional devices are also readily produced. With ring microresonator devices, active wavelength division multiplexing, optical network reconfiguration, and laser frequency tuning are straightforwardly accomplished.