Asymmetric hyperbolic metamaterials and their applications for light absorption and amplification

In this paper we demonstrate possibilities, offered by asymmetric hyperbolic metamaterials (HMM), for photonics. Asymmetric HMMs (AHMMs) are media, with optical axes, tilted with respect to interfaces. Asymmetry appears as a difference in properties of waves propagating upward and downward to interfaces that causes unusual properties of AHMMs. The most important feature of AHM is a possibility to excite a very slow wave in AHM by a plane wave, incoming from free space, while a minimal reflection may be achieved. Using graphene-based periodic structure as an example of AHMM, we consider absorption and amplification of terahertz radiation in optically ultra-thin layers of AHMM.