Design Synthesis And Characterization Of Polymeric Materials With Second Order Optical Nonlinearity PDF Download

This project consisted of four tasks each dealing with a different class of nonlinear optical materials. Task (U): Second-Order material. During the past year we used theoretical and experimental studies to develop a new class of materials in which a commonly used electron donor chromophore was replaced by a thiophene ring. To efficiently pole a second-order ionic chromophore, the use of a bulky counter-ion in order to reduce ionic conductivity was demonstrated. We also investigated the imagineary part of X(2) by electro-absorption. Task (II): Third-Order Materials. We synthesized a group of phosphoylides which contain a polarizable P atom. Their X(3) behavior were experimentally investigated using femtosecond Kerr gate. Using our new method of optically heterodyned and phase-tuned Kerr gate method, we investigated both the signs and the magnitudes of the real and the imaginary components of X(3). We showed that in the case of one-photon saturation, the sign of imaginary part is negative, while for two-photon absorption, this sign is positive. A very efficient two-photon induced fluorescence was also found for another nonlinear chromophore, diethylaminonitrostyrene, in the crystalline form. Task (III): photorefractive polymeric composites.