method of construction of polymeric materials with properties elettroottiche nonlinear second order and devices elettroottici made with these materials.

摘要

Process for realization of polymeric materials with second order nonlinear electro-optical properties and electro-optical devices made with said material The present concerns a process for realization of polymeric materials with second order nonlinear electro-optical properties comprising the following steps: - mixing of a chromophore with nonlinear optical properties with two or three hydroxy groups in an isocyanate not reactive solvent containing an isocyanate compound with at least two isocianate groups in order one or more bi- or tri-isocyanate NLO chromophores to be obtained; - isolation of said pure bi- or tri-isocyanate NLO chromophores obtained according to the above step; - dissolution of said bi- or tri-isocyanate NLO chromophores obtained according to the above step in one or more isocyanate group not reactive solvents containing reactive substances consisting of acyl-substituted or unsubstituted formamides and/or acylamides bearing as nitrogen substituents, independently, one or more hydrogen atoms, one or more alkyls substituted or unsubstituted with isocyanate moiety not reactive groups, one or more phenyl groups substituted or unsubstituted with isocyanate moiety not reactive groups, in order to obtain a prepolymer mixture consisting of said not reactive solvents and reaction products of said NLO bi- or tri-isocyanate chromophores and said reactive substances; - coating of a thin layer of said prepolymer mixture on a substrate and evaporation of said not reactive solvents; - cross-linking and poling of said thin layer on substrate, by means of heating and application of an electric field, in order a cross-linked and poled thin layer to be obtained; - cooling of said thin cross-linked and poled layer at ambient temperature maintaining the applied poling electric field; - switching off the poling electric field. The invention further concerns a process for the realization of an electro-optical device by definition of optical paths and driving electrodes in a polymeric material with second order nonlinear properties, comprising, following the steps of realization of said polymeric material with second order nonlinear electro-optical properties as previously defined, a step set of photolithographic definition and ionic erosion of said polymeric material, after a step for coating of a protecting buffer layer on said polymeric material layer, so as to maintain constantly embedded said layer of polymeric material in the areas involved in optical path realization during all the successive photolithographic definition and ionic erosion steps.