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Electrical and Optical Characterization of Fabricated Carbon-Based Multilayer Structure versus Temperature
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor) ; Zamani, Atieh (Co-Supervisor)
Abstract
This study presents a comprehensive investigation into the characterization of three distinct homogeneous multilayer self-standing thin films, composed of stacked reduced graphene oxide (rGO) planes, which were synthesized using a modified Hummer’s method. In order to investigate their structural, electrical, and optical properties, the samples were characterized by field emission scanning electron microscopy (FESEM), Raman spectroscopy, four-point probe measurements, Impedance measurements, Fourier-transform infrared spectroscopy (FTIR), and Time domain Terahertz Spectroscopy (TDS). The FESEM images obtained from the samples reveal a smooth sheet-like surface with few wrinkles....
Parallel-plate waveguide integrated filters and lenses realized by metallic posts for terahertz applications
, Article International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, 25 September 2016 through 30 September 2016 ; Volume 2016-November , 2016 ; 21622027 (ISSN) ; 9781467384858 (ISBN) ; Sharif University of Technology
IEEE Computer Society
2016
Abstract
In this paper, we report on the design and analysis of filters and lenses realized by an array of metallic posts integrated in a parallel-plate waveguide (PPWG). The design methodology of these components is inferred from the modal analysis of a spoof surface plasmonic waveguide composed of metallic posts arranged in a 1D periodic structure inside PPWG. Samples of the proposed devices are analyzed using a full-wave analysis method and their performance is assessed. We show that the mentioned structure can be used to realize all-metallic band-pass filters and lenses for mm-wave and terahertz applications
Effective medium theory for graphene-covered metallic gratings
, Article Journal of Optics (United Kingdom) ; Volume 18, Issue 10 , 2016 ; 20408978 (ISSN) ; Bagheri, A ; Khavasi, A ; Mehrany, K ; Sharif University of Technology
Institute of Physics Publishing
Abstract
We propose an effective medium theory for a one-dimensional periodic array of rectangular grooves covered by a graphene sheet. Parameters of the effective medium model are given by explicit analytical expressions for both major polarizations TM and TE, and for all incident angles. In extraction of this model, we assumed single mode approximation inside the grooves. The effect of non-specular diffraction orders outside the grating, as well as the plasmonic response of the graphene sheet in the far-infrared spectrum, is addressed by introducing an effective surface conductivity at the interface of the metallic grating and the ambient environment. It is shown that surface plasmons in graphene...
Waveguiding characteristics of a metal-clad dielectric grating for terahertz applications
, Article Optics Communications ; Volume 476 , 2020 ; Ahmadi Boroujeni, M ; Abbaszadeh, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Dielectric gratings (DGs) have recently been introduced as a new platform for guiding dielectric-based geometrically-induced surface plasmons (SPs) called spoof SPs (SSPs). In this paper, we report on the modal analysis of a metal-clad DG waveguide and compare its performance with other counterparts including the dielectric image guide (IG) and the metal grating (MG) waveguide. The proposed DG waveguide is made up of a periodic array of high-resistivity silicon (HR-Si) pillars on a metal plate with a metal cladding at a proper distance above the structure. By modal analysis of 2D and 3D structures, we show that the presence of the metal cladding enhances the modal field confinement without...