Michail M Sigalas

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It is shown, for the first time, that the transmittivity of wave guides created as rectilinear defects in periodic elastic band-gap materials oscillates as a function of frequency. The results are obtained using the finite difference time domain method for elastic waves propagating in two-dimensional inhomogeneous media. The oscillations of the(More)
The field enhancement in the gap between two Si microdisks is theoretically investigated using the finite difference time domain method. We show that the electric field within this gap increases as the distance between the two disks decreases, and it can be enhanced by as much as two orders of magnitude. By perturbing the Si microdisks to force the field(More)
We calculate the average transmission for sand p-polarized electromagnetic ~EM! waves and consequently the localization length of two-dimensional ~2D! disordered systems which are periodic on the average; the periodic systems form a square lattice consisting of infinitely long cylinders parallel to each other and embedded in a different dielectric medium.(More)
We theoretically study three-dimensional metallic photonic-band-gap ~PBG! materials at near-infrared and optical wavelengths. Our main objective is to find the importance of absorption in the metal and the suitability of observing photonic band gaps in this structure. For that reason, we study simple cubic structures and the metallic scatterers are either(More)
We have experimentally demonstrated the guiding, bending, and splitting of electromagnetic ~EM! waves in highly confined waveguides built around three-dimensional layer-by-layer photonic crystals by removing a single rod. Full transmission of the EM waves was observed for straight and bended waveguides. We also investigated the power splitter structures in(More)
We study the transmission of electromagnetic waves propagating in three-dimensional disordered photonic crystals that are periodic on the average with a diamond symmetry. The transmission has been calculated using the transfer matrix method. We study two different geometries for the scatterers: spheres and rods connecting nearest neighbors. We find that the(More)
The simplest anharmonic characteristics of Ir and Rh are discussed in the framework of a previously developed simple pseudopotential model which describes the elastic moduli, phonon spectra and the lattice heat capacity in the harmonic approximation of these metals succesfully. The microscopic Gruneisen parameters, the dependences of the elastic moduli on(More)
In this work we numerically examine structures which could confine light in nanometer areas. A system consisting of two silicon disks with in plane separation of a few tens of nanometers has been studied first. The normalized unitless effective mode volume, Veff, has been calculated for the two lowest whispering gallery mode resonances. The effective mode(More)
We quantitatively analyze the structure of thin film inverse-opal photonic crystals composed of ordered arrays of air pores in a background of titania. Ordering of the sphere template and introduction of the titania background were performed simultaneously in the thin film photonic crystals. Nondestructive optical measurements of backfilling with high(More)
We designed and fabricated multilayer metal/metal-oxide surface relief diffractive grating structures by growing alternating Pt and SnO(x) layers. Optical interrogation at 633 nm reveals the temperature dependence of their reflection and transmission diffractive effects. This function is explored here in the context of a remote, spatially localized,(More)
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