Increase of photoinduced birefringence in a new type of anisotropic nanocomposite: azopolymer doped with ZnO nanoparticles

We report a significant increase of about 50% of the photoinduced birefringence in nanocomposite films of azopolymers doped with ZnO nanoparticles compared with samples made from nondoped azopolymers. This increase is most pronounced at small concentrations of the nanoparticles of 0.5% and for the amorphous polymers used in our study. We observe also an improvement of the response time of more than 25% in some of the polymers, which allows for faster and more effective polarization optical recording.