| abstract |
The invention relates to the use in non-linear optics of azo dyes of formula I and the use of polymers containing azo dyes which include as characteristic monomer units bivalent groups derived from an azo dye of formula (I) wherein: D represents the residue of a diazo component derived from an aniline or from a five-membered aromatic heterocyclic amine whose heterocyclic ring includes one to three heteroatoms chosen from the group nitrogen, oxygen and sulphur and which can be anellated by a benzene, thiophene, pyridine or pyrimidine ring; R?1 and R2¿ represent, independently of each other, hydrogen, C¿1?-C6-alkyl or C5-C7-cycloalkyl; and R?3 and R4¿ represent, independently of each other, hydrogen or C¿1?-C6 alkyl which can be substituted by hydroxyl, acryloyloxyl or methacryloyloxyl, at least one of the two groups R?1 and R2¿ not being hydrogen. |