Direct observation of ultraslow hyperbolic polariton propagation with negative phase velocity
| Autor: | Martin Schnell, Oihana Txoperena, Achim Woessner, Fèlix Casanova, Alexey Y. Nikitin, Mark B. Lundeberg, Frank H. L. Koppens, Luis E. Hueso, Edward Yoxall, Rainer Hillenbrand |
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| Přispěvatelé: | Universitat Politècnica de Catalunya. Institut de Ciències Fotòniques |
| Rok vydání: | 2015 |
| Předmět: |
Physics
Física [Àrees temàtiques de la UPC] Condensed matter physics Phonon Phase (waves) Polaritons Polarització (Llum) Physics::Optics Metamaterial 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials 010309 optics Negative refraction propagation 0103 physical sciences Polariton Group velocity Spontaneous emission Phase velocity 0210 nano-technology |
| Zdroj: | Recercat. Dipósit de la Recerca de Catalunya instname UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) |
| ISSN: | 1749-4893 1749-4885 |
| Popis: | Time-domain interferometry and near-field scanning microscopy are used to investigate infrared phonon polaritons exhibiting hyperbolic dispersion. Negative phase velocity and group velocity as small as 0.002c are confirmed. Polaritons with hyperbolic dispersion are key to many emerging photonic technologies, including subdiffraction imaging, sensing and spontaneous emission engineering1,2,3,4,5,6,7,8. Fundamental to their effective application are the lifetimes of the polaritons, as well as their phase and group velocities7,9. Here, we combine time-domain interferometry10 and scattering-type near-field microscopy11 to visualize the propagation of hyperbolic polaritons in space and time, allowing the first direct measurement of all these quantities. In particular, we study infrared phonon polaritons in a thin hexagonal boron nitride8,12,13 waveguide exhibiting hyperbolic dispersion and deep subwavelength-scale field confinement. Our results reveal—in a natural material—negative phase velocity paired with a remarkably slow group velocity of 0.002c and lifetimes in the picosecond range. While these findings show the polariton's potential for mediating strong light–matter interactions and negative refraction, our imaging technique paves the way to explicit nanoimaging of polariton propagation characteristics in other two-dimensional materials, metamaterials and waveguides. |
| Databáze: | OpenAIRE |
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