Resonantly overcoming metal opacity

摘要: The near-perfect response of electrons in metals to low-frequency electromagnetic fields makes even a sub-skin-depth film almost completely opaque microwave radiation. Here, it is experimentally demonstrated that by surrounding ∼60 nm aluminium with an array thin resonant cavities, over 35% the radiation incident can be transmitted discrete set narrow bands. This represents enhancement ∼1000 times isolated and allows for frequency selective screen thickness less than 1/70th operating wavelength may tuned through choice geometry.