Physics / Fizik

Permanent URI for this collectionhttps://hdl.handle.net/11147/6

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Access Right: Open AccessAuthor: search.filters.author.Sözüer, Hüseyin Sami

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Fully Three-Dimensional Analysis of a Photonic Crystal Assisted Silicon on Insulator Waveguide Bend
    (World Scientific Publishing, 2018) Eti, Neslihan; Çetin, Zebih; Sözüer, Hüseyin Sami
    A detailed numerical study of low-loss silicon on insulator (SOI) waveguide bend is presented using the fully three-dimensional (3D) finite-difference time-domain (FDTD) method. The geometrical parameters are optimized to minimize the bending loss over a range of frequencies. Transmission results for the conventional single bend and photonic crystal assisted SOI waveguide bend are compared. Calculations are performed for the transmission values of TE-like modes where the electric field is strongly transverse to the direction of propagation. The best obtained transmission is over 95% for TE-like modes.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 12
    High Transmission Through a 90° Bend in a Polarization-Independent Single-Mode Photonic Crystal Waveguide
    (The Optical Society, 2015) Erol, Adem Enes; Sözüer, Hüseyin Sami
    We propose a polarization-independent single-mode waveguide, using a two-dimensional square photonic crystal with a complete band gap. The waveguide is tuned such that both TE and TM modes have the same group velocity and zero group velocity dispersion at the centergap frequency. We also present results for a 90° bend with transmission values of 98% for both modes.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 4
    Photonic Crystal Assisted 90° Waveguide Bend
    (World Scientific Publishing Co. Pte Ltd, 2011) Sözüer, Hüseyin Sami; Şengün, Hediye Duygu
    The 90° waveguide bend is an important component of optical circuit applications. We propose several models for such a bend, some of them assisted by a two-dimensional photonic crystal with a bandgap in the desired range of operating frequencies. We show that a photonic crystal assisted bend reduces bending loss by several orders of magnitude for transverse electric modes. © 2011 World Scientific Publishing Company.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 18
    Robustness of One-Dimensional Photonic Band Gaps Under Random Variations of Geometrical Parameters
    (American Physical Society, 2005) Sözüer, Hüseyin Sami; Sevim, Koray
    The supercell method is used to study the variation of the photonic bandgaps in one-dimensional photonic crystals under random perturbations to thicknesses of the layers. The results of both plane wave and analytical band structure and density of states calculations are presented along with the transmission coefficient as the level of randomness and the supercell size is increased. It is found that with the supercell size fixed at 1024 unit cells, higher bandgaps disappear first as the randomness is gradually increased. The lowest bandgap is found to persist up to a randomness level of 55%. However, as the supercell size is increased all bandgaps are observed to approach pseudogaps but with very low density of states. It is shown that harmonics of a relatively small cluster of closely spaced defects largely account for the bulk of the modes that populate the photonic bandgaps.