Asymmetric absorption at custom wavelengths via a layered magnetoelectric window

The controllable nonreciprocal propagation of light is an intensively investigated field of optics, with studies motivated both by fundamental questions and possible telecommunication applications. So far, polarization-independent, switchable one-way transparency has been demonstrated only at certain resonances of multiferroic crystals at cryogenic temperatures and in high magnetic fields, limiting the practical implementation of this effect. Here, as an alternative approach, we present the one-way transparency of an artificial layered structure consisting of split-ring metamaterial and magnetic substrate layers interacting in the dynamic regime. As evident from our quasioptical experiments in the GHz frequency range, this unique combination breaks time and space inversion symmetries in external magnetic field. The ease of tuning the dynamic response and the possibility of controllable one-way transparency make this approach promising for real-world applications.