Fig. 5: Manipulation of hyperbolic polaritons with artificial structures.
From: Broadband near-infrared hyperbolic polaritons in MoOCl2
a Optical image of a representative MoOCl2 flake (~ 60 nm) with etched ring slits. b PEEM images at different wavelengths with x-polarization at normal incidence, for the ring slit marked in (a). The yellow dashed lines indicate the focusing of hyperbolic polaritons outside the ring slit. c, d Schematics of internal propagation and external nanofocusing induced by the curvature of ring slit in real and k spaces, respectively. In (c), the colors indicate the electric field intensity (low in blue and high in red). e, f Polarization control for another ring slit on a ~ 50 nm MoOCl2 flake in real and k spaces, respectively.
