Polarization eigenstates analysis of helically structured thin films.

The optical properties of thin films are generally determined by direct photometric quantities. We show that additional insight into the properties of anisotropic thin films can be obtained by computing the polarization eigenstates and eigenvalues of their Jones matrices. We consider helically structured thin films, which display intriguing optical response, such as the circular Bragg resonance.

Observation of exceptional points in helically structured thin films.

Exceptional points (EPs) in the polarization space were observed in reflection on helically structured thin films. These films have form anisotropy at the nanoscale introduced through dynamic control of crystalline growth geometry by changing the orientation of the substrate with respect to the impinging vapor. They are simpler alternatives to metasurfaces, because they can be produced at low cost using conventional thin-film deposition techniques.