oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Photonic bandgap plasmonic waveguides  [PDF]
Andrey Markov,Carsten Reinhardt,Bora Ung,Andrey B. Evlyukhin,Wei Cheng,Boris N. Chichkov,Maksim Skorobogatiy
Physics , 2011, DOI: 10.1364/OL.36.002468
Abstract: A novel type of a plasmonic waveguide has been proposed featuring an "open" design that is easy to manufacture, simple to excite and that offers a convenient access to a plasmonic mode. Optical properties of photonic bandgap (PBG) plasmonic waveguides are investigated experimentally by leakage radiation microscopy and numerically using the finite element method confirming photonic bandgap guidance in a broad spectral range. Propagation and localization characteristics of a PBG plasmonic waveguide have been discussed as a function of the wavelength of operation, waveguide core size and the number of ridges in the periodic reflector for fundamental and higher order plasmonic modes of the waveguide.
An investigation of the effect of intermediate layer in three-component planar photonic crystal waveguides  [PDF]
Hongjun Shen,Huiping Tian,Yuefeng Ji
Optica Applicata , 2009,
Abstract: The introduction of a third component into planar photonic crystal waveguides definitely influences the properties of linear defect modes, such as the band diagram, intrinsic loss, group velocity and group velocity dispersion. With the increase of the dielectric constant of the interlayer, the guided modes shift to lower frequencies and the radiative losses decrease in the frequency region of high group velocity of defect mode. The analysis of the sensitivity of a band diagram to the introduction of an interlayer reveals that the wider the planar photonic crystal waveguide and the thicker the slab, the more tolerant the overall structure. When one designs the real planar photonic crystal waveguides, the effect of unintentional intermediate layer on the optical properties of planar photonic crystal waveguides has to be taken into consideration. At the same time, the introduction of an intentional interlayer into macroporous planar photonic crystal waveguides can be utilized to optimize the design.
Analysis and Applications of Uniplanar Compact Photonic Bandgap Structures
C. Chang;Y. Qian;T. Itoh
PIER , 2003, DOI: 10.2528/PIER02010890
Abstract: This paper reviews recent advancements in the research and development of Uniplanar Compact Photonic Bandgap (UCPBG) structures for microwave and millimeter-wave applications. These planar periodic structures are particularly attractive and have been intensively investigated due to their easy fabrication, low cost, and compatibility with standard planar circuit technology. In this paper, basic properties of UC-PBG will be studied such as the slowwave effect, distinct stopband and passband, leakage suppression of surface waves, and realization of a magnetic surface. Owing to the different features of UC-PBG, these structures have been applied to microwave circuits to improve microstrip filters and patch antennas, to perform harmonic tuning in power amplifiers, to suppress leakage in conductor-backed coplanar waveguide, to realize TEM waveguides, and to implement low-profile cavity-backed slot antennas.
Design of Optomechanical Cavities and Waveguides on a Simultaneous Bandgap Phononic-Photonic Crystal Slab  [PDF]
Amir H. Safavi-Naeini,Oskar Painter
Physics , 2010, DOI: 10.1364/OE.18.014926
Abstract: In this paper we study and design quasi-2D optomechanical crystals, waveguides, and resonant cavities formed from patterned slabs. Two-dimensional periodicity allows for in-plane pseudo-bandgaps in frequency where resonant optical and mechanical excitations localized to the slab are forbidden. By tailoring the unit cell geometry, we show that it is possible to have a slab crystal with simultaneous optical and mechanical pseudo-bandgaps, and for which optical waveguiding is not compromised. We then use these crystals to design optomechanical cavities in which strongly interacting, co-localized photonic-phononic resonances occur. A resonant cavity structure formed by perturbing a "linear defect" waveguide of optical and acoustic waves in a silicon optomechanical crystal slab is shown to support an optical resonance at wavelength 1.5 micron and a mechanical resonance of frequency 9.5 GHz. These resonances, due to the simultaneous pseudo-bandgap of the waveguide structure, are simulated to have optical and mechanical radiation-limited Q-factors greater than 10^7. The optomechanical coupling of the optical and acoustic resonances in this cavity due to radiation pressure is also studied, with a quantum conversion rate, corresponding to the scattering rate of a single cavity photon via a single cavity phonon, calculated to be 292 kHz.
Adaptation by Schottky Contact Coupled Lines for Planar Antennas on Photonic Bandgap
O. Tekkouk,K. Kemih,M. Benslama,H. Baudrand
International Journal of Electrical and Power Engineering , 2012,
Abstract: The antennas manufactured on photonic crystal used as substrate, are multi-bands and are by consequent not adapted always well to the lines which feed them. It is often necessary to resort to geometrical modifications on the drivers to cure with the problem of the loss of adaptability line-antenna. We propose a device of adaptation by Schottky contact coupled lines on semiconductor which makes it possible to modify the parameters of the feeders of antenna by the means of the tension.
Isotropic Band Gaps and Freeform Waveguides Observed in Hyperuniform Disordered Photonic Solids  [PDF]
Weining Man,Marian Florescu,Eric Paul Williamson,Yingquan He,Seyed Reza Hashemizad,Brian Y. C. Leung,Devin Robert Liner,Salvatore Torquato,Paul M. Chaikin,Paul J. Steinhardt
Physics , 2013, DOI: 10.1073/pnas.1307879110
Abstract: Recently, disordered photonic media and random textured surfaces have attracted increasing attention as strong light diffusers with broadband and wide-angle properties. We report the first experimental realization of an isotropic complete photonic band gap (PBG) in a two-dimensional (2D) disordered dielectric structure. This structure is designed by a constrained-optimization method, which combines advantages of both isotropy due to disorder and controlled scattering properties due to low density fluctuations (hyperuniformity) and uniform local topology. Our experiments use a modular design composed of Al2O3 walls and cylinders arranged in a hyperuniform disordered network. We observe a complete PBG in the microwave region, in good agreement with theoretical simulations, and show that the intrinsic isotropy of this novel class of PBG materials enables remarkable design freedom, including the realization of waveguides with arbitrary bending angles impossible in photonic crystals. This first experimental verification of a complete PBG and realization of functional defects in this new class of materials demonstrates their potential as building blocks for precise manipulation of photons in planar optical micro-circuits and has implications for disordered acoustic and electronic bandgap materials.
Microstructured and Photonic Bandgap Fibers for Applications in the Resonant Bio- and Chemical Sensors  [PDF]
Maksim Skorobogatiy
Journal of Sensors , 2009, DOI: 10.1155/2009/524237
Abstract: We review application of microstructured and photonic bandgap fibers for designing resonant optical sensors of changes in the value of analyte refractive index. This research subject has recently invoked much attention due to development of novel fiber types, as well as due to development of techniques for the activation of fiber microstructure with functional materials. Particularly, we consider two sensors types. The first sensor type employs hollow core photonic bandgap fibers where core guided mode is confined in the analyte filled core through resonant effect in the surrounding periodic reflector. The second sensor type employs metalized microstructured or photonic bandgap waveguides and fibers, where core guided mode is phase matched with a plasmon propagating at the fiber/analyte interface. In resonant sensors one typically employs fibers with strongly nonuniform spectral transmission characteristics that are sensitive to changes in the real part of the analyte refractive index. Moreover, if narrow absorption lines are present in the analyte transmission spectrum, due to Kramers-Kronig relation this will also result in strong variation in the real part of the refractive index in the vicinity of an absorption line. Therefore, resonant sensors allow detection of minute changes both in the real part of the analyte refractive index (10−6–10−4 RIU), as well as in the imaginary part of the analyte refractive index in the vicinity of absorption lines. In the following we detail various resonant sensor implementations, modes of operation, as well as analysis of sensitivities for some of the common transduction mechanisms for bio- and chemical sensing applications. Sensor designs considered in this review span spectral operation regions from the visible to terahertz.
Fractal Photonic Crystal Waveguides  [PDF]
Juan A. Monsoriu,Carlos J. Zapata-Rodriguez,Enrique Silvestre,Walter D. Furlan
Physics , 2004, DOI: 10.1016/j.optcom.2005.03.032
Abstract: We propose a new class of one-dimensional (1D) photonic waveguides: the fractal photonic crystal waveguides (FPCWs). These structures are photonic crystal waveguides (PCWs) etched with fratal distribution of grooves such as Cantor bars. The transmission properties of the FPCWs are investigated and compared with those of the conventional 1D PCWs. It is shown that the FPCW transmission spectrum has self-similarity properties associated with the fractal distribution of grooves. Furthermore, FPCWs exhibit sharp localized transmissions peaks that are approximately equidistant inside the photonic band gap.
The Leaky Spectrum of Bandgap Photonic Crystal Fibers
带隙型光子晶体光纤的泄露谱分析

The Modern Optics Institute of NanKai University,Tianjin,
刘建国
,开桂云,薛力芳,张春书,王志,李燕,孙婷婷,刘艳格,董孝义

光子学报 , 2006,
Abstract: The leaky spectrum of Photonic crystal fibers(PCF) was simulated with beam propagation method.The results showed that the leaky spectrum usually had several bandgaps,which would provide theoretical reference for designing a novel multi-band filter.Furthermore,the leaky spectrum was very sensitive to the PCF structure,the spectrum was affected not only by the period of the air hole but also by its dimension.Finally,the liquid crystal(LC) could be infiltrated in the air holes of the PCF,because the refractive index of LC could be tuned by controlling the voltage and the temperature.The peak leaky wavelength and bandgap wavelength would red shift with the LC refractive index increasing,which would provide reference for designing a novel tunable filter and optical switch by controlling the voltage or tune the LC temperature.
Feasibility of detecting single atoms using photonic bandgap cavities  [PDF]
Benjamin Lev,Kartik Srinivasan,Paul Barclay,Oskar Painter,Hideo Mabuchi
Physics , 2004, DOI: 10.1088/0957-4484/15/10/010
Abstract: We propose an atom-cavity chip that combines laser cooling and trapping of neutral atoms with magnetic microtraps and waveguides to deliver a cold atom to the mode of a fiber taper coupled photonic bandgap (PBG) cavity. The feasibility of this device for detecting single atoms is analyzed using both a semi-classical treatment and an unconditional master equation approach. Single-atom detection seems achievable in an initial experiment involving the non-deterministic delivery of weakly trapped atoms into the mode of the PBG cavity.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.