High-performance one-way transmission using pyramid-shaped silicon grating-coupled hyperbolic metamaterial

An asymmetric transmission device has been presented to realize high-performance one-way transmission at visible frequencies. This device consists of a pair of non-symmetric pyramid-shaped silicon gratings separated by a metal/dielectric multilayer structure (MDMS). Simulation results demonstrates that, compared with conventional Cr grating, MDMS with pyramid-shaped silicon gratings will greatly enhance the coupling and decoupling between the propagating waves in free space and the high frequency modes in MDMS, rendering an improved oneway transmission performance. The improved one-way transmission performance offered by our design may hold great potential in designing the optical isolator and polarizer for ultra-compact photonic integrated circuit.