Boosting Goos-Hänchen shift and reflectance in Dirac semimetal based photonic crystal heterostructure

Abstract Overcoming the inherent trade-off between Goos-Hänchen (GH) shift magnitude and reflectance, we demonstrate simultaneously giant GH shift enhancement (up to 8467 λ , λ represents the wavelength of the incident wave) and near-unity reflectance (0.98) in a bulk Dirac semimetal (BDS)-based one dimensional photonic crystal (1DPC) heterostructure. This synergistic enhancement of the GH shift and reflectance at a specific frequency arises from the concurrent excitation of a topological edge state (TES) at the interface between two asymmetric 1DPCs and an optical Tamm state (OTS) at the BDS/1DPC interface. Furthermore, the substantial GH shift in this heterostructure is dynamically tunable by adjusting the Fermi level of the BDS and the periodic number of the 1DPCs. This work establishes a novel BDS-based topological photonic platform enabling both large GH shifts and high reflectance, providing a theoretically viable design for high-sensitivity optical sensors and robust photonic devices.