Chiral metasurfaces based on arrays of Co nanospirals obtained by glancing angle deposition

The results of experimental studies of chiral film structures based on arrays of cobalt nanospirals obtained by glancing angle deposition are presented. It is shown that under conditions of electron beam evaporation, an array of nanospirals twisted in one direction is formed on a rotating inclined substrate. By changing the rotation speed of the substrate, the geometric dimensions of the nanospirals (spiral pitch, spiral radius) can be changed. The chiral metasurface obtained in this way demonstrates a pronounced asymmetry of optical characteristics in light reflection with respect to the right and left circular polarization. The experimental results confirm the dependence of these effects on the chirality signs of the obtained samples (that is, on the direction of twisting of the nanospirals).