A5025240255- Electromagnetic Scattering and Analysis
- Advanced Antenna and Metasurface Technologies
- Microwave Imaging and Scattering Analysis
- Metamaterials and Metasurfaces Applications
- Numerical methods in inverse problems
- Electromagnetic Simulation and Numerical Methods
- Optical Coatings and Gratings
- Ultrasonics and Acoustic Wave Propagation
- Photonic and Optical Devices
- Electromagnetic Compatibility and Measurements
- Antenna Design and Analysis
- Microwave Engineering and Waveguides
- Photonic Crystals and Applications
- Nonlinear Photonic Systems
- Microwave and Dielectric Measurement Techniques
- Acoustic Wave Phenomena Research
- Antenna Design and Optimization
- Geophysical Methods and Applications
- Electrical and Bioimpedance Tomography
- Plasmonic and Surface Plasmon Research
- Optical Polarization and Ellipsometry
- Orbital Angular Momentum in Optics
- Advanced Fiber Optic Sensors
- Random lasers and scattering media
- Electromagnetic wave absorption materials
Aristotle University of Thessaloniki
2016-2025
National Technical University of Athens
2005-2021
Aalto University
2015
Pennsylvania State University
2012
National Polytechnic School
2010
National and Kapodistrian University of Athens
2005-2009
Athens State University
2008
Starting from Maxwell's equations, we use the reductive perturbation method to derive a second-order and third-order nonlinear Schrödinger equation, describing ultrashort solitons in left-handed metamaterials. We find necessary conditions exact bright dark soliton solutions of these equations for electric magnetic field envelopes.
Plane wave scattering by a planar metasurface composed of two periodically alternating rectangular dielectric rods is considered. A rigorous integral equation methodology employed for the analysis and accurate determination reflected transmitted fields. Systematic optimizations with respect to configuration's parameters are performed, which reveal that it possible obtain significantly enhanced anomalous reflection (with simultaneously suppressed ordinary predicted Snell's law) power varying...
Eliminating the electromagnetic interaction of a device with its background is topic which attracts considerable attention both from theoretical as well an experimental point view. In this work, we analyze infinite two‐dimensional planar microstrip antenna, excited by incident plane wave, and propose potential operation low‐profile receiving suitably adjusting parameters cloaking superstrate. We impose semi‐analytic integral equation method to determine scattering characteristics antenna....
Methods employing auxiliary sources are applied to electromagnetic scattering problems by 2-D noncircular scatterers. Specific cases considered for which the singularities of analytic continuation scattered field into interior scatterer can be analytically determined. Then, it is shown that amplitudes (currents) diverge and oscillate when curve does not enclose these singularities. Still, electric fields computed means divergent oscillatory currents convergent correct. The correctness...
Multiple scattering problems involving point-source excitation of lossy media are considered. The sound fluxes induced by the interactions between scattered fields analyzed. Theorems connecting interaction intensities (active and reactive) with Lagrangian densities cross sections established. Physical bounds regarding ratios derived, highlighting contribution interaction-induced to overall intensity. Explicit results for lossless clusters given. case a cluster composed point-like scatterers is also
Abstract Photonic nanorods with multiple concentric layers are found to exhibit giant polarization selectivity when absorbing power from near-field sources. An improved version of Chaotic Accelerated Particle Swarm Optimization (CAPSO) is developed and employed determine various designs for several combinations alternating dielectric plasmonic media, operated under visible light different colors. The spatial distribution the electromagnetic intensity unveils nature sustained resonances...
Multiple scattering problems involving point-source excitation of lossy media are considered. The sound fluxes induced by the interactions between scattered fields analyzed. Theorems connecting interaction intensities (active and reactive) with Lagrangian densities cross sections established. Physical bounds regarding ratios derived, highlighting contribution interaction-induced to overall intensity. Explicit results for lossless clusters given. case a cluster composed point-like scatterers is also
Abstract The perturbation of a magnetostatic field by torus made homogeneous anisotropic magnetic material was formulated using the solutions Laplace equation in toroidal coordinate system. That straightforward
in region outside torus, but an affine transformation had to be employed inside torus. The
coefficients series expansion potential terms appropriate basis functions
were related coefficients source functions transition matrix. As a
result solution this...
Several wave scattering phenomena in optics are modeled by the method of fictitious sources (MFS). Despite its interesting features, effectiveness MFS and applicability restricted open issues, including placement (FS) fields’ convergence. Concerning these we investigate here convergence study oscillations solutions for a representative problem dielectric cylinder illuminated current filament. It is shown analytically that, when FS radii lie interior exterior two disks with certain critical...
Color-selective absorption of light is a very significant operation used in numerous applications, from photonic sensing and switching to optical signal modulation energy harnessing. We demonstrate angle-insensitive polarization-independent by thin bilayers comprising ordinary bulk media: dielectrics, semiconductors, metals. Several highly efficient designs for each color the visible spectrum are reported, their internal fields' distributions reveal resonance mechanism absorption. The...
Steering the incoming photonic power toward unusual directions, not predicted by Snell's laws of reflection and refraction, is a fundamental operation behind numerous wavefront engineering applications. In this study, strong anomalous transmission reported to all-dielectric electrically thin structures comprising only two materials in alternating rectangular posts. These binary metagratings have been thoroughly optimized support almost perfect negative refraction suppressing all rest...
In this work, the auxiliary-current vector norm (ACVN)-based method of auxiliary sources (MAS) is extended and employed for computation cutoff wavenumbers (or eigenvalues) arbitrarily shaped, perfectly electric conducting (PEC) waveguides, having anisotropic permittivity permeability infills. To solve problem, cross-sectional domain waveguide excited by a line-source current. Then, eigenvalues are extracted as which ACVNs maximized. We prove analytically that, in special case circular...
A spherical electromagnetic wave is scattered by a layered sphere. The exact expressions of the and interior fields are obtained solving corresponding boundary-value problem, means combination Sommerfeld's T-matrix methods. recursive algorithm with respect to number layers extracted for computation in every layer. far-field pattern scattering cross-sections determined terms physical geometrical characteristics scatterer. As point-source tends infinity, known results plane incidence...
Diffraction of electromagnetic waves by periodic grating waveguides is investigated using a rigorous integral equation method, which combines semianalytical techniques and the Method Moments with entire domain basis functions. The electric field employed unknown function on grooves. This subsequently solved applying an Galerkin's technique. proposed analysis provides high numerical stability controllable accuracy. All involved computations are analytically carried out, leading to analytic...
A sphere excited by an interior point source or a dipole gives simplified yet realistic model for studying variety of applications in medical imaging. We suppose that there is exterior field (transmission problem) and the total on known. give analytical inversion algorithms determining physical characteristics as well location, strength orientation source/dipole. start with static problems (Laplace’s equation) then proceed to acoustic (Helmholtz equation).
Starting from the Maxwell equations, we used reductive perturbation method to derive a system of two coupled nonlinear Schr\"{o}dinger (NLS) equations for Beltrami components electromagnetic field propagating along fixed direction in an isotropic chiral metamaterial. With single-resonance Lorentz models permittivity and permeability Condon model chirality parameter, certain spectral regimes, one exhibits negative real refractive index when nonlinearity is ignored parameter sufficiently...
The method of auxiliary sources (MAS) is one the numerical methods employed for determination cutoff wavenumbers (eigenvalues) cylindrical waveguides. According to general scheme MAS, eigenvalues are obtained by requiring square impedance matrix be singular and therefore its determinant zero (or condition number large). For large matrices, such computations complicated time-consuming. Additionally, these schemes frequently contaminated with spurious eigenvalues. To overcome difficulties, an...
The Method of Auxiliary Sources (MAS) is an established technique for the numerical solution electromagnetic (EM) scattering and radiation problems. This paper presents a hybrid MAS with Fast Multipole (FMM), which provides strategy reducing computational cost solving large-scale problems without notable accuracy loss (and in reasonable time). MAS-FMM scheme applied to problem EM from arbitrarily large array lossless/lossy dielectric cylinders. Numerical results are presented verify schemes,...