Fig. 2: Dependence on illumination orientation of HShPs in a bulk bGO crystal.
From: Controlling the propagation asymmetry of hyperbolic shear polaritons in beta-gallium oxide
a–e Experimental near-field images of HShP propagation, launched by a 2 µm gold disc at a frequency of 712 cm−1, with FEL illumination rotated in 45-degree steps, as illustrated by a white dashed line. f–j Finite element modeling of HShP propagation from gold disc, with illumination conditions similar to (a–e). k–o Fourier transforms of f–j, illustrating the shear asymmetry in the polariton propagation. The red dashed curves in k–o are the dispersion of HShPs calculated from theory.
