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Journal: Optik

Abbreviation

Optik (Stuttg.)

Publisher

Elsevier

Journal Volumes

ISSN

0030-4026
1618-1336

Description

Filters

2008 - 200912010 - 20144
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Publications1 - 5 of 5
  • Plasmonic planar lens based on stack of metal-insulator-metal waveguides with height tuning
    Item type: Journal Article
    Zheng, G. G.; Xiao, S. R.; Zhang, C. Y.; et al. (2013)
    Optik
    We introduce a technique capable of focusing electromagnetic (EM) waves through plasmonic nanoslits symmetrically arranged along the indented semi-circular surface in silver background. The EM transports through the tuning slits in the form of surface plasmon polaritons (SPPs), and gets the required phase retardations to focus at the focal plane. Due to the subwavelength nature of planar metallic lens, we present the rigorous electromagnetic analysis by using two dimensional (2D) finite difference time domain (FDTD) method. These height-modulated slits with uniform width are demonstrated to have unique advantages in beam manipulation. In combination with previous studies, it is expected that our structure with small number of slits could lead to realization of optimum designs of plasmonic nano-lens. © 2013 Elsevier GmbH.
  • Beam bending through compound structure with two subwavelength metallic slits in each period
    Item type: Journal Article
    Zheng, Gaige; Xu, Linhua; Wu, Yigen; et al. (2014)
    Optik
    To provide a more practical, easy-to-implement method to achieve directional modulation with a plasmonic lens, beam manipulation method via compound metallic gratings with two subwavelength slits filled with different dielectrics inside each period is proposed and numerically investigated by finite-difference time-domain (FDTD) method. Compared with conventional metal-grating based structures, phase retardation is tuned by the Fabry-Pérot (FP) resonant condition and light bending is achieved by constructing a carefully designed, curved phase front for the plasmonic lenses. Our designs have advantages in ease of fabrication and capability to perform in the far field. With these advantages, the designs are expected to be valuable in applications such as plasmonic circuits and photonic communication. © 2013 Elsevier GmbH.
  • Wavelength-division-multiplexing system with photonic crystal self-collimation and co-directional coupling effect
    Item type: Journal Article
    Zheng, G.G.; Wang, Z.S.; Zhao, D.L.; et al. (2014)
    Optik
    A wavelength-division-multiplexing system with high compactness and extremely simple structures is designed and analyzed theoretically for optical communication wavelengths. The structure consists of a self-collimation region, a coupler, a coupling section, and two arbitrarily bent periodic dielectric waveguides (PDWGs). Operation principle of the devices is based on self-collimation and directional coupling mechanism. The equal-frequency contours (EFCs) are nearly flat from 0.17-0.22 (2πc/a), thus the self-collimation region acts as a multiplexer. Operation principle of the demultiplexer is based on directional coupling in two parallel periodic dielectric waveguides. The device performances have been evaluated by the finite-difference time-domain simulations coupled with perfectly matched layer (PML) boundary conditions. © 2014 Elsevier GmbH. All rights reserved.
  • Communication modes in scalar diffraction
    Item type: Journal Article
    Martinsson, Per; Ma, Ping; Burvall, Anna; et al. (2008)
    Optik
    The communication modes are a useful concept in studies of optical resolution, wave propagation, and image synthesis. We present an overview of earlier results on the communication modes in scalar diffraction theory. Besides the general theory, the modes are reviewed for the far-field and Fresnel regimes, and new eigenequations are derived for wide-angle diffraction. We prove a conjugate relationship between the transmitting and receiving modes in a general symmetric system. We also suggest an approximate method for far-field and Fresnel domain propagation, in which propagation amounts to a rotation of each mode in the complex plane. The main focus is on the near-field communication modes, where we present numerical examples of the modes and coupling strengths for a near-field geometry with a sub-wavelength size receiving domain. These results provide insights, for example, into the understanding of near-field scanning probe techniques. © 2006 Elsevier GmbH. All rights reserved.
  • Communication modes in vector diffraction
    Item type: Journal Article
    Martinsson, Per; Lajunen, Hanna; Mac, Ping; et al. (2010)
    Optik
    The communication modes, which mathematically correspond to singular value decomposition, have proven a useful concept in optical scalar-field diffraction, with applications in resolution studies, image synthesis, and wave propagation. For optical near-field geometries the communication modes have to be extended to electromagnetic field accounting for the polarization properties. In this paper we present the vector-valued communication modes method based on the rigorous electric-field diffraction integral. As a special case the transverse-electric scalar field modes are obtained. The intensity and polarization properties of the leading electromagnetic communication modes in near-field arrangements with rectangular apertures are discussed in terms of the Stokes parameters. For small separations between the transmitting and receiving apertures the fundamental mode possesses a ring-shaped hollow structure. The polarization properties of the near-field modes show features on spatial scales smaller than the wavelength of light. The system symmetries lead to degenerate communication modes. © 2009 Elsevier GmbH All rights reserved.
Publications1 - 5 of 5