All-metal metasurface polarization converter in visible region with an in-band function

We propose an ultrathin and high-efficiency all-metal metasurface polarization converter, by which cross-polarization conversion in reflection mode is achieved for linearly-polarized lights. The simulated result shows that the polarization conversion ratio for normal incidence is nearly 100% in the visible region. Moreover, strong coupling between nanobars with metallic ground plane, make it possible to provide novel application of in-band switch function. The proposed all-metal polarization converter not only improves the feasibility of nanofabrication due to its simple nanostructure, but demonstrates a reflection-type avenue to design optoelectronic devices up to the visible spectrum. (C) 2019 The Japan Society of Applied Physics