Abstract-Wideband backscattering reduction at terahertz using compound reflection grating

Bakhtiyar Orazbayev, Pablo Rodríguez-Ulibarri, and Miguel Beruete

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-25-19-22905&origin=search

Backscattering reduction is usually achieved by using either absorbers or diffractions gratings at the expense of a narrow bandwidth. In this paper, we propose a different strategy based on a metallic compound reflection grating (CRG). We demonstrate that this structure allows a strong and broadband (fractional bandwidth, FBW ≈57%) backscattering reduction in the terahertz (THz) range by efficiently transferring the incident energy to the diffracted modes. The design is analyzed in terms of equivalent circuit and numerical simulations and the results are corroborated by a manufactured prototype operating at 0.35 THz.

© 2017 Optical Society of America

Abstract-Terahertz epsilon-near-zero graded-index lens

Víctor Torres, Víctor Pacheco-Peña, Pablo Rodríguez-Ulibarri,Miguel Navarro-Cía, Miguel Beruete, Mario Sorolla, and Nader Engheta  »View Author Affiliations

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-21-7-9156

An epsilon-near-zero graded-index converging lens with planar faces is proposed and analyzed. Each perfectly-electric conducting (PEC) waveguide comprising the lens operates slightly above its cut-off frequency and has the same length but different cross-sectional dimensions. This allows controlling individually the propagation constant and the normalized characteristic impedance of each waveguide for the desired phase front at the lens output while Fresnel reflection losses are minimized. A complete theoretical analysis based on the waveguide theory and Fermat’s principle is provided. This is complemented with numerical simulation results of two-dimensional and three-dimensional lenses, made of PEC and aluminum, respectively, and working in the terahertz regime, which show good agreement with the analytical work.

© 2013 OSA