Synthesis and Z-scan measurements of third-order optical nonlinearity of azothiazole- and azobenzothiazole-containing side-chain polymers

A series of aromatic azothiazole and azobenzothiazole compounds containing vinyl have been designed as monomers. The polymers containing azothiazole and azobenzothiazole NLO chromophore in each side chain have been synthesized via free radical polymerization. The third-order NLO coefficient of monomers containing azothiazole and azobenzothiazole and their polymers were measured by Z-scan technique. The conjugation and push–pull electronic effect on the heteroatomic ring group contributes much to enhancing the NLO property.