New photocrosslinkable maleimide copolymers have been synthesized by the attachment of a tricyanopyrrolidene-based chromophore. The 243-cyano-442-14[hexyl-(6-hydroxy-hexyl)-aminol-phenyl]-vinyl)-5-oxo-1-{ 4-[4-(3-oxo-3-phenyl-propenyl)-phenoxy-butyl}-1,5-dihydro-pyrrol-2-ylidene)-malononitrile chromophore exhibits nonlinear optical activity and contains a chalcone moiety that is sensitive to UV light (lambda). = 330-360 nm) for crosslink formation. The maleimide monomers have also been functionalized. with chalcone moieties. The resultant copolymers exhibit great processability, and one of them shows a maximum electrooptic coefficient of 90 pm/V at 1300 nm. We could control the thermal stability of the electrooptic coefficient with the newly synthesized photoreactive copolymers successfully. (c) 2006 Wiley Periodicals, Inc.