One-way sheet absorbers

In this presentation we discuss electrically thin layers (sheets supporting induced electric and magnetic surface currents) which fully absorb power of normally incident plane waves when illuminated from one side. The question which we address is what functionalities we can realize for waves coming from the opposite direction? We show that possible new functionalities due to reciprocal and nonreciprocal field coupling in the layer include ultimately thin isolators, artificial magnetic conductors, and twist polarizers.