Coexistence of giant Goos-Hänchen shift and high reflectance in Dirac semimetal based multilayered structure.

Abstract

Bulk Dirac semimetals (BDSs) possess Fermi energy dependent optical parameters, providing unprecedented opportunities for the study of the controllable Goos-Hänchen (GH) shift. However, the enhancement of GH shifts often comes at the cost of the reflectance in the previous BDS-based structures, which hinders their practical application. In this work, we theoretically present the investigation of the GH shift in a multilayered structure composed of one BDS film and a symmetric one-dimensional photonic crystal (1DPC) with a defect layer. We demonstrate that this well-designed structure supports a large GH shift at the specific working wavelength, whose magnitude can be enhanced up to 3883 times the incident wavelength. In particular, such an enhanced GH shift achieved in this structure is associated with high reflectance (0.94) and these remarkable features can be attributed to the sharp change in the reflective phase and the destructive interference that occurs between the simultaneously excited optical Tamm state (OTS) at the BDS/1DPC interface and the defect state at the 1D defected PC. In addition, we also explore the manipulation of the GH shift by adjusting the Fermi energy of the BDS as well as the geometrical parameter of the multilayered structure. Our results provide a new approach for realizing an enhanced and controllable GH shift in a BDS-based multilayered structure, which endows it with promising prospects for application in optical sensors, optical detectors and beam controllers.