Transformation of Light Polarization Using Nanoporous Alumina Films

The polarization transformations of light interacting with nanoporous alumina films were investigated theoretically and experimentally. It was shown that a compact device based on nanoporous alumina film could be designed to control light polarization by functioning in various regimes, in particular, as quarter-wave and half-wave plates. It was established that the regimes could be switched from one to another by varying the film orientation relative to the incident light beam. It was found that quasi-circularly polarized light beams with a wide angular spectrum could be formed in a broad spectral region by using the nanoporous alumina film.