Focusing of in-plane hyperbolic polaritons in van der Waals crystals with tailored infrared nanoantennas
[EN]Phonon polaritons (PhPs)-light coupled to lattice vibrations-with in-plane hyperbolic dispersion exhibit ray-like propagation with large wave vectors and enhanced density of optical states along certain directions on a surface. As such, they have raised a surge of interest, promising unprecedent...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/54155 |
| Acceso en línea: | http://hdl.handle.net/10810/54155 |
| Access Level: | acceso abierto |
| Palabra clave: | phonon polaritons |
| Sumario: | [EN]Phonon polaritons (PhPs)-light coupled to lattice vibrations-with in-plane hyperbolic dispersion exhibit ray-like propagation with large wave vectors and enhanced density of optical states along certain directions on a surface. As such, they have raised a surge of interest, promising unprecedented manipulation of infrared light at the nanoscale in a planar circuitry. Here, we demonstrate focusing of in-plane hyperbolic PhPs propagating along thin slabs of alpha-MoO3. To that end, we developed metallic nanoantennas of convex geometries for both efficient launching and focusing of the polaritons. The foci obtained exhibit enhanced near-field confinement and absorption compared to foci produced by in-plane isotropic PhPs. Foci sizes as small as lambda(p)/4.5 = lambda(0)/50 were achieved (lambda(p) is the polariton wavelength and lambda(0) is the photon wavelength). Focusing of in-plane hyperbolic polaritons introduces a first and most basic building block developing planar polariton optics using in-plane anisotropic van der Waals materials. |
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