SYNTHESIS AND PROCESSING OF IMPROVED ORGANIC 2ND-ORDER NONLINEAR-OPTICAL MATERIALS FOR APPLICATIONS IN PHOTONICS

The synthesis and processing steps required to fabricate prototype ele ctrooptic modulators from poled polymeric materials containing nonline ar optical chromophores are reviewed. These include (I) synthesis of c hromophores with large first hyperpolarizabilities, (2) covalent incor poration of these chromophores into polymer lattices which can be proc essed into optical-quality thin films and poled by application of elec tric fields, (3) induction of lattice-hardening reactions which lock-i n poling-induced noncentrosymmetric order, (4) creation of buried chan nel, nonlinear optical waveguides by reactive ion etching, by electron cyclotron resonance etching, and/or by photochemical processing, (5) coupling of buried channel electrooptic modulators to fiber optic tran smission Lines by photochemical processing and silicon V-groove pigtai ling, (6) deposition of metal drive electrodes and evaluation of resul ting prototype modulators. While the focus of this article is upon the synthesis and processing of materials, some consideration is given to device concepts including various Mach-Zehnder modulators, birefringe nce modulators, directional couplers, photonic voltage sensors, and ph otonic detection of electromagnetic radiation. Although poled polymers are of primary interest, other techniques for ultrastructure synthesi s of noncentrosymmetric lattices are reviewed, including molecular sel f-assembly, sequential synthesis, and laser-assisted poling.