A novel polyelectrolyte (PBANT-AC) functionalized with branched electron donating-accepting azobenzene chromophores has been synthesized through post-polymerization azo coupling reaction and characterized by 1H-NMR

FTIR and UV-Vis spectrometry．The degree of functionalization (DF) of PBANT-AC was 17％ measured by elemental analysis．The degree of polymerization and its distribution were determined by GPC to be Xn=588 with a polydispersion index 1.3．A glass transition temperature of 139℃ was observed from DSC thermogram．H-Aggregation of azo chromophores of PBANT-AC in H2O-THF mixed solvent was detected from UV-Vis spectra and controlled by the ratio of VTHF／VH2O. The H-aggregates in water-tetrahydrofuran mixture were successfully fabricated into self-assembled multilayers with poly (diallydimethylammonium cloride) by an electrostatic layer-by-layer process．Birefringence and dichroism were optically induced in the self-assembled films under the irradiation of a polarized Ar+ laser beam at 488 μm．The resulting dichroism was easily detected from UV-Vis spectra and exhibited long-term stability．The orientational order parameter obtained was 0.05 for the film. Upon irradiation

the H-aggregates of azo chromophores were changed to ‘isolated’ form after the cis-trans isomerization．