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THz wave sensing at ETRO-VUB: beyond conventional limits Host Publication: THz wave sensing at ETRO-VUB: beyond conventional limits Authors: V. Matvejev, A. Pourkazemi, H. Alkorre, G. Shkerdin and J. Stiens Publisher: Springer Publication Date: Jan. 2017 Number of Pages: 12 ISBN: 978-94-024-1092-1
Abstract: Here, we demonstrate a novel Terahertz (THz) wave characterization technique and modulation devices developed at ETRO-IR (VUB) that facilitate the detection of Chemical Biological Radiation and Nuclear (CBRN) hazards. First, a novel transient radar technique is presented for a Non-Destructive Testing (NDT) of a multilayered dielectric object. A transient reflected electromagnetic wave is captured with femtosecond time resolution, so it can be able to reconstruct both the dielectric and thickness information from multitude of scattered waves from different dielectric interfaces in a multilayered object. A blind reconstruction algorithm does not require any priori knowledge of the object under test. Proof-of-principle is demonstrated experimentally at 10 GHz on a three-layered object, featuring subwavelength depth resolution. Second, amplitude and phase modulators are proposed based on hollow metal pipe waveguide loaded with single layer graphene on a dielectric substrate. It is demonstrated that the modes propagation constants can be substantially modulated by the graphene Fermi level modulation especially near the regions of strong mode modifications. Solutions of wave propagation equations are given and design parameters are optimized for implementing an efficient Terahertz modulator devices. Fast 3D object scanning and detection of CBRN hazards can be implemented in THz by means of transient radar with phased antenna array with graphene phase shifting modulators.
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