| abstract |
The invention relates to an NLO side chain polymer which exhibits low optical attenuation and is obtainable by reacting an NLO monomer in the form of a difunctional compound comprising a donor-(pi)-acceptor group with at least a first comonomer in the form of a difunctional compound reactive towards the NLO monomer and comprising an organic group, with hydrogen atoms in the organic group which is part of the first comonomer having been replaced by heavier elements such as deuterium or halogen, notably fluorine and/or chlorine. The comonomer may be per-substituted; alternatively, use may be made of two or more comonomers of different substitutions. More particularly, the invention relates to NLO polyesters, polycarbonates and polyurethanes made up of D(pi)A group-containing dihydroxy compounds and deuterated or halogenated dicarboxyl compounds, bischloroformates or diisocyanates known in themselves. The polymers are used as waveguides in, for instance, electro-optical devices such as an optical switch. |