Angle-independent coupling between topological interface states and Tamm states in photonic crystal heterostructures with hyperbolic metamaterials

In this study, we report an angle-independent coupling mechanism between topological interface states and Tamm plasma polaritons within a photonic crystal heterostructure with hyperbolic metamaterials. The heterostructure is formed by two distinct photonic crystals, which have angle-independent photonic bandgaps through phase variation control. By analyzing the Zak phases of the upper and lower bands, we find that these two photonic bandgaps exhibit opposite topological characteristics, leading to the emergence of an angle-independent topological interface state. The metal layer at the bottom of the photonic crystal enables the excitation of Tamm plasmon polaritons; strong coupling with topological interface states is achieved, resulting in a dual-mode, wide-angle, polarization-dependent absorber with two distinct regions. The results reveal a straightforward approach for realizing angle-independent coupling between topological interface states and Tamm plasmonic polaritons, with promising applications in sensors, absorbers, optical filters, and nonlinear optical devices.