Spatial shifts of reflected light beam on black phosphorus/hexagonal boron nitride structure

Abstract

We examined Goos-Hänchen (GH) and Imbert-Fedorov (IF) shifts of the reflective beam from the hexagonal boron nitride (hBN) covered by black phosphorus (BP) layers, where the BP layers are rotated by an angle with respect to the incident plane. The interaction of phonon polaritons in hBN and plasmon polaritons in BP, as well as the structure surface and interface between the two media determines the two shifts. In the common frequency–response range of the BP and hBN, the GH- and IF-shifts can be very large in the vicinity of epsilon-near-zero (ENZ) for a linearly-polarized incidence. The GH-shift can be continuously tuned from positive to negative or even to zero at a fixed frequency by adjusting the electron density and anisotropic axis-orientation of the BP. Another fascinating phenomenon is that the IF-shift can be not only excited by the linearly-polarized incidence but also greatly improved, even up to -156λ0. These conclusions are applicable to the other 2D anisotropic materials, which will become a guidance of new polarization-dependent, anisotropic optoelectronics devices.