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2014, 2(1) Column

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Photonics Research 第2卷 第1期

Author Affiliations
Abstract
Fiber Optics Group, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
A highly accurate, fully analytic solution for the continuous wave and the probe wave in Brillouin amplification, in lossless optical fibers, is given. It is experimentally confirmed that the reported analytic solution can account for spectral distortion and pump depletion in the parameter space that is relevant to Brillouin fiber sensor applications, as well as applications in photonic logic. The analytic solutions are valid characterizations of Brillouin amplification in both the low and high nonlinearity regime, for short fiber lengths.
Photonics Research
2014, 2(1): 01000001
Author Affiliations
Abstract
1 Center for Optoelectronics and Optical Communications, The University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, North Carolina 28223, USA
2 Department of Chemistry, The University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, North Carolina 28223, USA
3 Department of Electrical and Computer Science, The University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, North Carolina 28223, USA
Coupled plasmonic nanoparticles of Au and nanorods of ZnTe are modeled and fabricated. Full-wave simulation is performed to obtain an optimum design for enhanced light absorption and to explain scattering properties of the structure. The fabrication method of such arrays is described. Modeling the spectral properties using equivalent circuit theory is also implemented to provide an intuitive approach regarding the design of optical metamaterials with predetermined properties.
Photonics Research
2014, 2(1): 01000010
Author Affiliations
Abstract
1 Microelectronics and Photonics Graduate Program, University of Arkansas, Fayetteville, Arkansas 72701, USA
2 Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
Fano resonances between plasmons and diffracted light offer tunable energies and locales, but attribution of Fano resonance features to geometry and physicochemistry of metal nanostructures and adjacent dielectrics has been confounded by complexity and computational expense. This work shows predictable modal shifts of Fano resonance in square lattices of plasmonic nanostructures can be attributed directly to changes in medium wavenumber, particle size, and lattice constant that alter plasmon polarizability and diffractive interference. For 45 to 80 nm radius particles, a window of lattice constants that support Fano resonances is identified in a range from 500 to 900 nm. Lattice constants that support high intensity resonances are determined by individual particle polarizability and medium wavenumber. Fano resonance wavelengths redshift from diffracted photon energies as local refractive index (RI) changes due to coupling with particle polarizability in the window. Redshift sensitivities for quadrupole, dipole, and Fano resonances are 150, 348, and 541 nm, respectively, per RI unit. Fano resonance intensity may be enhanced more than tenfold by selecting nanoparticle sizes and lattice constants. The quantitative effects of such parametric changes are rapidly and intuitively distinguished using a semi-analytic approach, consisting of an exact expression for particle polarizability, a trigonometric description of diffraction, and a semianalytical coupled dipole approximation.
Photonics Research
2014, 2(1): 01000015
Author Affiliations
Abstract
Laboratoire de Nanotechnologie et d’Instrumentation Optique, Institut Charles Delaunay, CNRS-UMR 6279, Universite de Technologie de Troyes, CS 42060, 10004, Troyes, France
The eigenmodes analysis of Bloch modes in a chain of metallic nanowires (MNWs) provides a significant physical understanding about the light propagation phenomena involved in such structures. However, most of these analyses have been done above the light line in the dispersion relation, where the Bloch modes can only be excited with radiative modes. By making use of the Fourier modal method, in this paper we rigorously calculate the eigenmode and mode excitation of a chain of MNWs via the fundamental transverse magnetic (TM) mode of a dielectric waveguide. Quadrupolar and dipolar transversal Bloch modes were obtained in an MNW chain embedded in a dielectric material. These modes can be coupled efficiently with the fundamental TM mode of the waveguide. Since the eigenmodes supported by the integrated plasmonic structure exhibit strong localized surface plasmon (LSP) resonances, they could serve as a nanodevice for sensing applications. Also, the analysis opens a direction for novel nanostructures, potentially helpful for the efficient excitation of LSPs and strong field enhancement.
Photonics Research
2014, 2(1): 01000024
Author Affiliations
Abstract
Physics Department, Southern Federal University Rostov-na-Donu, Zorge St. 5, 344090 Rostov-na-Donu, Russia
A vector integral–differential equation to describe electromagnetic wave propagation in nanowaveguides and photonic crystals containing thin metal layers is developed. Exact solution of the equation is obtained with the Galerkin method, taking into account the complex dielectric permittivity of metals in the optical range. A simple method for finding complex effective refractive indices for low-loss waveguide structures is developed and proved. Surface plasmon-polariton waves are simulated in the structures under consideration.
Photonics Research
2014, 2(1): 01000031
Author Affiliations
Abstract
1 State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
A novel polarimetric dehazing method is proposed based on three linear polarization images (0°, 45°, and 90°). The polarization orientation angle of the light scattered by the haze particles is introduced in the algorithm. No additional image-processing algorithm is needed in the postprocessing. It is found that the dehazed image suffers from little noise and the details of the objects close to the observer can be preserved well. In addition, this algorithm is also proved to be useful for preserving image colors. Experimental results demonstrate that such an algorithm has some universality in handling all kinds of haze. We think that this robust algorithm might be very suitable for real-time dehazing.
Photonics Research
2014, 2(1): 01000038