Loading...
Search for:
spoof-surface-plasmons
0.005 seconds
Understanding the role of slant angle in oblique slit arrays made of metal at terahertz frequencies
, Article IEEE Transactions on Terahertz Science and Technology ; Volume 5, Issue 3 , May , 2015 , Pages 497-504 ; 2156342X (ISSN) ; Mehrany, K ; Sharif University of Technology
IEEE Microwave Theory and Techniques Society
2015
Abstract
Analytical expressions are given for zeroth-order diffraction efficiencies of metallic gratings with slanted and straight slit arrays at microwave and terahertz frequencies when the slit width is small enough to ensure that non-principal eigenmodes supported by the slit remain below cut-off. These expressions show that at lower normalized frequencies when the grating is zeroth order and all off-specular diffraction orders are evanescent, metallic slit arrays with slanted and straight walls could become identical to each other whenever certain relation is held between the geometrical parameters of the two structures. A noteworthy advantage of juxtaposing slanted and slit arrays is that it...
Design of Impedance Surfaces with Metamaterials and Metasurfaces to Implement Line Wave
, M.Sc. Thesis Sharif University of Technology ; Khavasi, Amin (Supervisor)
Abstract
In this thesis we introduce line wave. Which propagates only in one direction and dissipate in other direction. Line wave can propagates at the interface of two complementary impedance surfaces. There are various ways to build a waveguide which can support line waves like complementary structures. In this thesis we try to find a way which will not use complementary structures. Hence we use Spoof Surface Plasmon Polariton concept to mimic complementary structure characteristics. A complementary surface-based waveguide consists of two parts; one part supports TE polarization waves and the other one supports TM polarization waves. When these TE and TM waves face each other in the boundary, line...
THz plasmonic devices based on an array of metallic posts in a parallel-plate waveguide
, Article International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, Mainz ; 2013 ; 21622027 (ISSN) ; 9781467347174 (ISBN) ; Shahabadi, M ; Altmann, K ; Sharif University of Technology
2013
Abstract
An array of metallic posts sandwiched between two parallel metal plates supports highly-confined surface waves that can be regarded as spoof surface plasmons. This structure which is called the parallel-plate ladder waveguide (PPLWG) can be used for implementing THz guided-wave devices. In this paper, the effect of post shapes on waveguiding characteristics of PPLWG is analyzed and realization of certain devices such as couplers using the proposed structure is investigated
Design of a hybrid spoof plasmonic sub-terahertz waveguide with low bending loss in a broad frequency band
, Article Optics Express ; Volume 25, Issue 6 , 2017 , Pages 6860-6873 ; 10944087 (ISSN) ; Ahmadi Boroujeni, M ; Sharif University of Technology
OSA - The Optical Society
2017
Abstract
The effect of dielectric cladding on the waveguiding characteristics of an array of metallic pillars on a metal plane in the sub-terahertz band is explored. Firstly, a 2D structure made up of a metallic grating of infinite lateral width with various dielectric overlays is analytically studied to get more insight into the problem. Then the ideas inferred from the 2D structure are applied to the realistic 3D structure that has a finite lateral width. It is shown that by proper design of the dielectric medium surrounding the metallic structure the modal field confinement can be enhanced in a broad frequency band resulting in a low bending loss. Especially, by integrating the pillars into a...
Second-Order mode analysis of spoof surface plasmon waveguide
, Article 30th International Conference on Electrical Engineering, ICEE 2022, 17 May 2022 through 19 May 2022 ; 2022 , Pages 161-165 ; 9781665480871 (ISBN) ; Shishegar, A. A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
This paper analyzes the second-order mode of the spoof surface plasmon (SSP) waveguide, which consists of PEC pillars (dominos) with finite lateral widths on a PEC ground. The space is first divided into four regions. The electromagnetic fields of each region are then written as TE and TM. The boundary conditions and matching integrals are employed to determine the dispersion relations of the second-order mode of the SSP waveguide consisting of two relations. Inspired by Marcatili's method, the analytical approach is to develop a recently-used method for the first mode of the SSP waveguide. The dispersion relations are then solved; therefore, the dispersion curve is plotted. The analytical...
Physics of broadband Brewster transmission through square array of rectangular metallic pillars
, Article Journal of the Optical Society of America B: Optical Physics ; Volume 32, Issue 6 , 2015 , Pages 1202-1207 ; 07403224 (ISSN) ; Khavasi, A ; Mehrany, K ; Sharif University of Technology
OSA - The Optical Society
2015
Abstract
The physics behind the broadband Brewster transmission through square arrays made of rectangular metallic pillars is explored by appealing to the effective medium theory. First, an analytical solution is given for the principal electromagnetic mode propagating between the pillars, and then, the mode matching technique is invoked to extract the parameters of the effective medium model. In this fashion, the pillars are homogenized via a diagonal anisotropic tensor and the effects of higher diffracted orders are included in the effective medium theory by attributing a surface conductivity to the surface boundary of the array. It is shown that the former effectuates the wideband Brewster effect...
Tunable leaky-wave radiation by graphenecovered corrugated surfaces
, Article Applied Optics ; Volume 57, Issue 30 , 2018 , Pages 8971-8977 ; 1559128X (ISSN) ; Saba, A ; Arik, K ; Khavasi, A ; Sharif University of Technology
OSA - The Optical Society
2018
Abstract
we propose a graphene-covered subwavelength metallic grating where the Fermi level of graphene is sinusoidally modulated as a leaky-wave antenna at terahertz frequencies. This structure can convert spoof surface plasmon guided waves to free-space radiation due to the tunability of graphene. Analysis and design of the proposed leaky-wave antenna are discussed based on sinusoidally modulated surface impedance. The surface impedance is obtained by an analytical circuit model. The sinusoidal surface impedance is realized using modulation of the conductivity of graphene by applying a bias voltage. The proposed leaky-wave antenna is capable of electronic beam scanning with an almost constant gain...
Spoof surface plasmon analysis based on Marcatili's method
, Article Journal of the Optical Society of America B: Optical Physics ; Volume 37, Issue 11 , 2020 , Pages 326-3267 ; Shishegar, A. A ; Sharif University of Technology
OSA-The Optical Society
2020
Abstract
Motivated by surface plasmon polariton waveguides in the optical regime, spoof surface plasmon (SSP) waveguides have received a lot of attention in terahertz and millimeter wave frequencies.Most research on these kinds of waveguides is numerical. However, some limited analytical work can be seen in the literature. In this paper, one type of SSP waveguide that is composed of a rectangular corrugation with finite lateral width on the ground is considered, and an analytical method, which is inspired byMarcatili's method, is proposed in order to calculate the dispersion curve of the first mode. The results of this analytical method and a numerical commercial eigenmode solver are compared. The...
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...