Preparation of Stable Photopatternable Polymeric Materials for Non- linear Optics

Several new functionalized chromophores have been prepared and tested in the preparation of optically stable, photopatternable, NLO polymers for second harmonic generation at the diode laser wavelength of 820 nm. In particular, chromophores containing the sulfonamide or sulfonate ester functionalities have been found to be extremely versatile as they allow attachment of a polymerizable group at the electron-poor end of NLO chromophores. The results of model studies confirm that the sulfonamide groups do not have a deleterious effect on NLO properties. Several new monomers containing 4-alkoxy-4'- sulfonamido-stilbene moieties have been prepared. The 4- alkoxy end of the chromophore 'is designed to allow its incorporation into a linear polymer backbone. The sulfonamido end of the chromophore has a polymerizable double bond that can be photocrosslinked after poling of the chromophores. As it is extremely important to carry out the photopatterning step without affecting the NLO chromophore or introducing any color into the imaged polymer, novel photoinitiators were tested and found to be suitable. The radiation induced photo-patterning step can be done without causing isomerization of the stilbene chromophores, or introducing any color into the patterned coating