Reflectionless Refraction via One-Dimensional Ghost Polaritons in Planar Junctions of Hyperbolic Metasurfaces
Zhiwei He,
Huaping Wang,
Zhenyang Cui,
Sihao Xia,
Xingyu Tang,
Bin Zheng,
Xiao Lin,
Lian Shen,
Hongsheng Chen and
Yingjie Wu
Polaritons, part-light−part-matter waves, enable the control of light at the subwavelength scale. Interfacial behaviors play a critical role in polariton manipulation, with negative refraction showing promise for high-resolution focusing. However, reflections pose a substantial challenge, especially in applications where backscattering is unwanted. To address this issue, we propose a structure composed of planar junctions of metasurfaces, each supporting in-plane hyperbolic polaritons with misaligned optical axes. We demonstrate that when the asymptote of the incident hyperbolic isofrequency contours (IFCs) aligns with the interface normal, the reflected waves transform into highly lossy one-dimensional ghost polaritons (HL-1DGPs), channeling energy near the interface. The refracted waves also convert into HL-1DGPs when the outgoing IFC asymptote aligns with the interface normal. Leveraging these phenomena, we design polaritonic lenses and absorbers with greatly reduced reflection. These insights into the interfacial behaviors of hyperbolic polaritons under symmetry breaking have implications for creating polaritonic elements beyond the diffraction limit.
