Mechanically Tunable Metasurface Based on Free Standing Crossed Metal Bar Gratings with Adjustable Crossing Angle as a Tunable Filter

We study the resonant transmission of normally incident plane electromagnetic wave through the metasurface consisting of two overlapping one-periodic bar gratings with mechanically tunable crossing angle in free space. The bars of the gratings are made of PEC-like material of nonzero thickness. It was theoretically revealed and experimentally confirmed that the frequency of the sharp lattice resonance depends on the crossing angle and shifts towards higher frequencies if the crossing angle increases. It was shown theoretically that the lattice resonances split if the overlapping one-periodic bar gratings have different periods. Near field patterns above and below the structure were obtained at the frequencies of the resonance peaks.