Angle-insensitive all-optical diodes in a large range of incidence by photonic heterostructure containing hyperbolic metamaterials

We theoretically and systematically investigate angle-insensitive all-optical diodes using photonic heterostructures composed of different one-dimensional photonic crystals containing hyperbolic metamaterials. Hyperbolic metamaterials comprise metals with high nonlinear coefficients and transparent dielectrics. The results indicate that the photonic heterostructure shows angle insensitivity in transmittance, transmission contrast, and the critical intensity of the threshold over a large range of incidence, achieving a high transmission contrast of approximately 0.93 between forward and backward incident light. This angle insensitivity originates from the phase-variation compensation effect in a basic unit composed of hyperbolic metamaterials and transparent dielectric materials under TM polarization. These results provide important reference values for future experiments.