Abstract-Two-dimensional reversed Cherenkov radiation on plasmonic thin-film

Weihao Liu, Linbo Liang, and Qika Jia

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-25-15-18216&origin=search

The reversed Cherenkov radiation is one of the most attractive research topics because of its unique characteristics and promising applications. It was generally believed that reversed Cherenkov radiations exist only in left-handed metamaterials (double negative mediums). In the present paper, we demonstrated that they can also be generated on plasmonic thin-films. Reversed Cherenkov radiations in the terahertz region and in the visible light region were achieved on the metamaterial thin-film and the metal thin-film, respectively. Their radiation frequencies and directions, which are interdependent with each other, are controllable. For the normal Cherenkov radiation, the wavelength on the thin-film increases with the frequency; whereas for the reversed Cherenkov radiation, the opposite is true. Theoretical analyses and simulations revealed that the normal or reversed Cherenkov radiation is generated depending on whether the forward or backward surface modes are excited on the plasmonic thin-film. Requirements of these reversed Cherenkov radiations were found out.

© 2017 Optical Society of America

Abstract-Dielectric Concentrator for Cherenkov Radiation

Sergey N. Galyamin and Andrey V. Tyukhtin
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.064802

We report on a dielectric target that concentrates Cherenkov radiation into a small spatial area. In contrast to traditional devices, this target can focus almost all of the radiation without using additional lenses or mirrors. We consider the case where radiation is produced by a point charge moving along the axis of a cylindrical channel inside an axially symmetrical target. The specific form of the target is determined using the laws of ray optics. The field is calculated using an aperture integration method that can determine the field near the focus. Typical field plots and the spatial distribution of the field outside the target are presented. We demonstrate that at terahertz frequencies, this concentrator can increase the field magnitude by up to at least 2 orders of magnitude relative to that on the surface of the target.

DOI: http://dx.doi.org/10.1103/PhysRevLett.113.064802

• 
• 
• 

• Published 7 August 2014
• Received 20 March 2014

© 2014 American Physical Society