| Autor: |
Anton D. Zaitsev, Petr S. Demchenko, Natallya S. Kablukova, Anna V. Vozianova, Mikhail K. Khodzitsky |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Photonics, Vol 10, Iss 5, p 501 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2304-6732 |
| DOI: |
10.3390/photonics10050501 |
| Popis: |
Negative group delay may be observed in dispersive media with anomalous dispersion in a certain frequency range. The fact that an outgoing wave packet precedes an incoming one does not violate the causality principle but is only a consequence of a waveform reshaping. This effect is observed in media such as photonic crystals, hyperbolic and epsilon-near-zero metamaterials, undersized waveguides, subwavelength apertures, side-by-side prisms, and resonant circuits at various frequencies. The current work is devoted to the design of a simple negative-group-delay medium with tunable properties in the THz frequency range. This medium consists of a bismuth-based frequency-selective surface on a dielectric substrate and may be tuned both statically and dynamically. While a geometry variation defines a main form of an effective permittivity dispersion and group delay/group velocity spectra, an external voltage allows one to adjust them with high precision. For the configuration proposed in this work, all frequency regions with noticeable change in group delay/group velocity lie within atmospheric transparency windows, which are to be used in 6G communications. This medium may be applied to THz photonics for a tunable phase-shift compensation, dispersion management in systems of THz signal modulation, and for encoding in next-generation wireless communication systems. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
