Optical Tamm state and extraordinary light transmission through nanoaperture

We investigate the light transmission through a nanoaperture in a metal film deposited on a planar metamaterial. An effect of an anomalously high light transmission through the nanoaperture is revealed, which we associate with the enhancement of the field at the interface of the planar structure "metamaterial-metal" due to the appearance of an optical Tamm state. In this structure, we also observe an "optical diode" effect: the light transmission radically changes as the direction of irradiation of the structure is reversed. Our numerical results agree well with experimental data.