Abstract: Nonlinearly optically active monomer species comprising at least two carbon-carbon activated double bonds, i.e., the polymerization of which is facilitated by the presence of an electron attracting function, and a non-centrosymmetric system of pi (.pi.

Abstract: Novel nonlinearly optically active polymers, well suited for electrooptical applications, are prepared by copolymerizing a first difunctional monomer with a second difunctional comonomer, with at least one of such difunctional monomers including a polar charge transfer moiety containing at least one electron acceptor group and at least one electron donor group (D), and further wherein the polymerizable functional groups are borne by the one or more electron donor groups (D).

Abstract: The present invention relates to new thiphene-related compounds of the general formula (I): ##STR1## in which: n is an integer between 1 and 10, advantageously between 1 and 4;A is an electron-acceptor group; and D is an electron-donor group.These compounds exhibit a high hyperpolarizability and an excellent photochemical stability and are employed especially in optical or electrooptical devices for their activity in nonlinear optics.

Abstract: Marterials which are active in nonlinear optics, having a repeating unit of the following formula I: ##STR1## in which R.sub.1 and R.sub.2, are either identical or different, and denote a linear or branched methylenic chain, preferably containing from 2 to 6 carbon atoms; R.sub.3 is an aliphatic, aromatic or arylaliphatic hydrocarbon radical; R.sub.4 and R.sub.5, which are identical or different, denote a nitrogen atom or a CH radical, or alternatively R.sub.4 and R.sub.5 are both carbon with the R.sub.4 -R.sub.5 bond being a double or a triple bond; and Z.sub.1 and Z.sub.2, which are identical or different, denote an aromatic group wherein Z.sub.1 optionally contains one or more substituents R.sub.7 and wherein Z.sub.2 optionally contains one or more substituents R.sub.7 in addition to group A, each substituent R.sub.7 may be lower alkyl, halogen, amido, amino, sulfoxide, hydroxyl radical, alkoxy and trifluoromethyl; and A denotes an electron-acceptor group, with Z.sub.2 having one or more groups A.

Abstract: Novel nonlinearly optically active polyurethane polymers, well suited for electrooptical applications, have recurring structural units of the formula: ##STR1## in which m is a number greater than 5; R.sub.1 and R.sub.2, which may be identical or different, are each a saturated or unsaturated alkyl or aromatic radical; R.sub.3 is a linear aliphatic, or cyclic aromatic or arylaliphatic hydrocarbon radical; and Y is a group including a radical containing dislocated .pi. electrons and an electron acceptor group (A).