Temporal evolution of photoinduced optical chirality in nanostructured light-sensitive waveguide thin films: Simultaneous excitation of TE0 and TE1 modes

Optical properties of the self-organized gratings in thin photosensitive waveguide AgCl films on a glass substrate, doped by Ag nanoparticles, in the case of simultaneous excitation of TE0 and TE1 modes are investigated. These gratings are a result of interference of the incident linear polarized He-Ne laser beam with the excited TEn-modes of the AgCl layer. The interference field patterns the re-distribution of the nanoparticles. Each excited mode generates its own grating. The self-organized gratings associated with the TE0 mode appear earlier than that of the TE1 mode. There is a competition between TE0-gratings and TE1-gratings for absorbing the nanoparticles, because their available amount is limited in the interaction area. The competition is due to the positive feedback of the light mechanism. Thus, the TE1-grating removes some Ag nanoparticles from the already generated TE0-grating, which forms some chiral complex building blocks of the gratings. The induced chirality leads to the induction and en...