A modulator includes a voltage source, a first arrangement including first and second non-insulating layers configured such that a modulation voltage from the voltage source can be applied there across, and a second arrangement between the first and second non-insulating layers. The second arrangement includes a first amorphous layer configured such that a transport of electrons between the first and second non-insulating layers includes tunneling. The first arrangement further includes an antenna structure for absorbing part of an input radiation, while a remainder of the input radiation is reflected. The second arrangement cooperates with the first arrangement such that the antenna exhibits a first absorptivity, when a first modulation voltage is applied to the first arrangement, and exhibits a distinct, second absorptivity, when a second modulation voltage is applied, thereby causing the antenna to reflect a different amount of input radiation to an output as modulated radiation.