Diode-like asymmetric transmission in hyperbolic epsilon-near-zero media

Epsilon-near-zero (ENZ) media have attracted a great deal of interest since ENZregime is able to trigger secondary light-matter interactions such as nonlinear and nonlocal effects. Here, we show the boosting of asymmetric... [ view full abstract ]

Epsilon-near-zero (ENZ) media have attracted a great deal of interest since ENZ
regime is able to trigger secondary light-matter interactions such as nonlinear and nonlocal effects. Here, we show the boosting of asymmetric transmission for forward and backward propagation of tilted circular polarized optical waves in ultrathin epsilon-near-zero hyperbolic slabs. Remarkably, this effect is solely triggered by anisotropy without resorting to any breaking of reciprocityand chiral symmetries or spatial nonlocal effects. The ENZ enhancement is due to the fact that the hyperbolic dispersion activates etalon resonances where extraordinary waves accumulate propagation phase even though the slab is ultrathin. The proposed strategy holds promise for realizing ultra-compactand efficient polarization devices at different frequency bands.