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The purpose of this paper is to analyze far and near field emitted field patterns through more exact calculation of the modes formed in finite periodic dielectric gratings.

For the mode calculation, equations are newly defined by applying vertical boundary condition on the assumption that transverse electric modes are generated in the structure. After finding modes, near field patterns are calculated using the wave number and coefficient of the mode.

Additionally, the results from these calculations are compared with that of the rigorous-coupled method. Finally, far field patterns are derived by applying fast Fourier transform to near field patterns and also compared with the results of rigorous-coupled method.

For convenience of coordinate, we use rectangular coordinate, though the shape of radome is a hemisphere.

In this paper, the authors derive more exact near field patterns without the assumption of infiniteness so that these results can be used practically for a making real frequency-selective structure.

Conventional periodic finite dielectric gratings analysis has been done using Floquet–Bloch wave theory, coupled-mode, rigorous-coupled method which is based on the assumption of infiniteness of the structure.

The purpose of this paper is to develop a rigorous self-contained formulation for analyzing electromagnetic scattering by grating of plasmonic nanorods. The authors investigate this structure from the viewpoint of the practical application as a refractive index plasmonic sensor. The presented rigorous formulation is accompanied with a neat implementation providing a high computation efficiency and could be considered as an important tool for designing and optimizing compact sensors.

Scattering of an incident plane wave by grating made of a periodic arrangement of metal-coated dielectric nanocylinders on a dielectric slab is rigorously investigated using the recursive algorithm combined with the lattice sums technique. As a dielectric slab, the authors consider glass material, which is widely used in experiments, whereas silver (Ag) is used as a low loss metal suitable to excite plasmon resonances. The main advantage of the developed self-contained formulation is that first the authors extract the reflection and transmission matrices of a single planar array from a separate analysis of the grating and the slab and then obtain the scattering characteristics of the whole structure by using a recursive formula. The method is computationally fast.

Dependence of the surface plasmon resonance wavelength on the refractive index of the surrounding medium is carefully investigated. The resonance peaks are red-shifted with respect to an increasing refractive index of surrounding medium showing an almost linear behavior. Near field distributions are analyzed at the resonance wavelengths of the spectral responses. Special attention is paid to the formation of the dual-absorption bands because of the excitation of the localized surface plasmons. The authors give physical insight to the coupling between grating and the glass slab. The authors found that a strong enhancement of the field inside the slab occurs when the scattered wave of the grating is phase-matched to the guided modes supported by the slab.

In the authors’ formulation, they do not use any approximation and it is rigorous and accurate. The authors use their original method. The method is based on the lattice sums technique and uses the recursive algorithm to calculate the generalized reflection and transmission characteristics by grating. Such fast and accurate method is an effective tool apt for designing and optimizing tailored sensors, for e.g. advanced biomedical applications.

The purpose of this paper is to simulate and analyze the excitation and propagation of surface plasmon polaritons (SPPs) on sinusoidal metallic gratings in conical mounting.

Chandezon's method has been implemented in MATLAB environment in order to compute the optical response of metallic gratings illuminated under azimuthal rotation. The code allows describing the full optical features both in far- and near-field terms, and the performed analyses highlight the fundamental role of incident polarization on SPP excitation in the conical configuration.

Results of far-field polarization conversion and plasmonic near-field computation clearly show that azimuthally rotated metallic gratings can support propagating surface plasmon with generic polarization.

The recent papers experimentally demonstrated the benefits in sensitivity and the polarization phenomenology that are originated by an azimuthal rotation of the grating. In this work, numerical simulations confirm these experimental results and complete the analysis with a study of the excited SPP near-field on the metal surface.

The two‐dimensional discrete Huygens’ modelling or TLM simulation is presented for the TE electromagnetic field problems. The TLM element or node with variable traveling speed and characteristic impedance is applied to several practical problems including scattering at the edge of a wall and over periodic grids or grooves, wave propagation along a dielectric structure, and a mode coupling between two parallel optical waveguides. The TLM solutions are compared with the theoretical ones or the results of other numerical methods and reasonable agreement is achieved.

The purpose of this paper is to investigate a light-trapping structure based on Ag nanograting for amorphous silicon (a-Si) thin-film solar cell. Silver nanopillar arrays on indium tin oxide layer of the a-Si thin-film solar cells were designed.

The effects of the geometrical parameters such as nanopillar radius (R) and array period (P) were investigated by using the finite element simulation.

The optimization results show that the absorption of the solar cell with Ag nanopillar structure and anti-reflection film is enhanced up to 29.5 per cent under AM1.5 illumination in the 300- to 800-nm wavelength range compared with the reference cell. Furthermore, physical mechanisms of absorption enhancement at different wavelength range are discussed according to the electrical field amplitude distributions in the solar cells.

The research is still in progress. Further studies mainly focus on the performance of solar cells with different nanograting materials.

This study provides a feasible method for light-trapping structure based on Ag nanograting for a-Si thin-film solar cell.

This study is promising for the design of a-Si thin-film solar cells with enhanced performance.

This paper aims to design metaguide- or metasurface-based compact inexpensive beam-steering devices, which play an important role in modern cellular networks, radar imaging and satellite communication.

This paper uses finite element analysis to study, design and optimize arrays of resonating elements as beam steering devices. The first set of such devices involves metamaterial-based apertures fed by a waveguide, tunable via the permittivity of the host material. In the second approach, dynamic beam steering is effected by alternating between two or more waveguide feeds.

Particular examples show how the direction of the main lobe of the radiated beam can be reliably switched by approximately 30° in one of the quadrants by changing a single global control parameter within a very reasonable range.

The findings pave the way for the design and fabrication of inexpensive compact beam steering devices. This study anticipates that the proposed designs can be further improved and fine-tuned using “heavy duty” optimization packages.

In many published designs of similar beam-steering devices, the radiation pattern of an array of resonating elements is controlled by complex circuitry, so that each radiating element is tuned separately. In contrast with these existing approaches, the designs rely just on a simple global control parameter.

The purpose of this paper is to present the results of a particle swarm optimization (PSO) method applied in the design of a square-loop frequency selective surface (FSS) via the equivalent circuit model (ECM), considering the dielectric effective permittivity as a variable in the optimization problem.

In the optimization process considered, besides the FSS square loop geometric parameters, the thickness and relative permittivity of dielectric material used as support are included as variables in the search space, using for this a model of dielectric effective permittivity introduced by the authors in a previous work.

Square loops were designed and the obtained results were compared with designs reported in literature for applications in wireless local area network and long-term evolution 4G systems. The low computational cost is remarkable as well as the acceptable accuracy obtained with the proposed approach. The PSO method results were implemented with the ECM and compared with those obtained via Ansys – high frequency structure simulator commercial software simulations.

The lack of a model of dielectric effective permittivity for the ECM causes a restricted search space in the stochastic FSS design process limited to only geometric parameters, as it is reported in the available literature. The proposed approach simplifies and makes more flexible the design process, and allows guiding the FSS design to unit cell surface and/or dielectric thickness of small dimensions.

In this paper, we study a new class of optical fibers to be utilized in future optics and optoelectronics. These so‐called photonic band gap (PBG) waveguides can be classified into a fundamentally different way to all optical waveguides and possess radically different guiding properties due to PBG guidance, as opposed to guidance by total internal reflection.

The purpose of this study is to design a plasmonic structure that can be used simultaneously as a heater and a refractive index sensor applicable for heating and sensing cycles of lab-on-chip (LOC).

The authors report on the full optical method applicable in the heating and sensing cycles of LOC based on the plasmonic nanostructure. The novelty of this proposed structure is due to the fact that a structure simultaneously acts as a heater and a sensor.

In terms of the performance of the proposed structure as an analyte detection sensor, in addition to the real-time measurement, there is no need to labeling the sample. In terms of the performance of the proposed structure as a plasmonic heater, the uniformity and speed of the heating and cooling cycles have been greatly improved. Also, there is no need for experts and laboratory conditions; therefore, our proposed method can meet the conditions of point of care testing.

The authors confirm that this work is original and has not been published elsewhere nor it is currently under consideration for publication elsewhere.

A novel low profile frequency selective surface (FSS) with a band-stop response at 10 GHz is demonstrated. The purpose of this designed FSS structure is to reject the X-band (8-12 GHz) for the application of shielding. The proposed FSS structure having the unit cell dimension of 8 × 8 mm², the miniaturization of the FSS unit cell in terms of λ₀ is 0.266 λ₀ × 0.266 λ₀, where λ₀ is free space wavelength. The designed FSS provides 4 GHz bandwidth with insertion loss of 15 dB. The transverse electric (TE) and transverse magnetic (TM) modes of the proposed design are same because of polarization independent characteristics and hold the angularly stable frequency response for both TE and TM mode polarization. Both the simulation and measurement results are in good agreement to each other.

The proposed FSS design contains square-shaped PEC material, which is placed on the substrate and the shape of the circle and rectangle is etched over the PEC material. The PEC material of the patch dimension is 0.0175 mm. The substrate used for the proposed design is FR4 lossy with the thickness of 0.8 mm and permittivity εr = 4.3 having a loss tangent of 0.02.

To find a new design and miniaturized FSS structure is discussed.

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