Photonic
Mostrando 1-12 de 114 artigos, teses e dissertações.
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1. Optical Fiber Coupler Analysis Using Daubechies Wavelets
Abstract This article presents the theoretical analysis of a signal coupling between a proposed Photonic Crystal Fiber (PCF) and a Conventional Fiber with Step Index (CFSI) system. In this analysis, the Finite Element Method (FEM) and Beam Propagation Method (BPM) are applied together with Daubechies wavelets as basis function and described in the mathematic
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-09
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2. Highly birefringent do-octagonal photonic crystal fibers with ultra flattened zero dispersion for supercontinuum generation
Abstract Photonic crystal fiber (PCF) structures with do-octagonal geometry have been studied. These do-octagonal PCF structure have smaller circular holes arranged in rhombic fashion at its centre. Moreover, these small holes are doped with materials like butanol, ethanol, methanol and propanol. Do-octagonal PCF structures doped with methanol and air filled
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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3. Calculation of reflectance and transmittance of optical birefringent networks based on cholesteric liquid crystals
Abstract In this paper we calculated reflectance and transmittance of different optical birefringent networks sandwiched between two isotropic media. To model optical phenomena in the considered systems, we applied the 4×4 matrix method. Some interesting reflectance and transmittance spectra and polar plots for different system parameters and arbitrary inci
Lat. Am. j. solids struct.. Publicado em: 18/02/2019
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4. Directional Coupler Based on a Photonic Quasi-Crystal Fiber with Extended Cores
Abstract In this paper, an optical coupler composed by a photonic quasi-crystal fiber (PQCF) with two cores is proposed. The structure is obtained by immersion of a quasi-periodic arrangement of air holes replicated twelve-fold in a conventional fiber optical constituted of pure silica. The cores are generated from defects caused due to absence of two air ho
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-06
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5. Effects of Birefringence on the Electromagnetic Guidance of Structures Produced by Femtosecond Laser
Abstract Analysis of the state of polarization of light guided by structures recorded in lithium niobate and lithium fluoride crystals indicates that the recording method is determinant in the formation of birefringent structures. Each structure was written with a single and continuous translation of the crystal transversally to the laser beam. Birefringence
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-06
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6. Theoretical Approach to Simulate Efficient Selective Solar Absorbers With Micro or Nano Structured Arrays
Study of the solar absorber with photonic crystal or micro structures as the heat absorbing surfaces operated at a high-temperature was conducted. Numerical calculations based on rigorous coupled-wave analysis were performed to determine the absorptance of the photonic crystal surface on the absorber. The effect of nano geometry of the photonic crystal in tu
Mat. Res.. Publicado em: 22/03/2018
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7. Novel Design of Photonic Digital Sensors for Distinguishing Uniformly-Distributed Refractive Indices of Fluids
Abstract The authors propose a novel structure of k-level (k is an arbitrary integer) photonic digital sensor based on directional couplers with specific structural parameters. Its function is similar to an analog-to-digital converter (ADC) in electronic system, and capable of distinguishing 2k+1-1 discrete and uniformly-distributed refractive indices of the
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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8. Analysis of the Propagation Properties of 90°-bend Periodic Segmented Waveguides Using the 2D Finite Element Method
Abstract We use the two dimensional finite element method (2D-FEM) in the frequency domain to characterize the transmission properties of 90°-bend periodic segmented waveguides (PSWs). We investigated the dependence of the transmission coefficient and the mode profile of PSWs on the bending radius, the waveguide duty cycle, and the operating wavelength. We
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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9. An Analytical Solution for Fiber Optic Links with Photonic-Assisted Millimeter Wave Upconversion Due to MZM Nonlinearities
Abstract Photonic-assisted technique employed in the generation of stable and high-purity signals in the millimeter wave band has been investigated using dual-parallel Mach-Zehnder modulator. Indeed, this type of generation performs a high order RF multiplier, whose operation principle steams out from the nonlinear characteristic of the external modulators.
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-03
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10. Optically controlled reconfigurable antenna for 5G future broadband cellular communication networks
Abstract This paper presents an optically controlled reconfigurable antenna for millimetre-wave frequency range. Silicon switches are used to control the optical reconfiguration, modifying the frequency response and radiation pattern of the antenna design. Therefore, the system can switch between the lightly licensed 28 GHz and 38 GHz frequency bands, useful
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-03
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11. Design and Modal Analysis of Photonic Crystal Fiber for Dispersion Compensation over Broadband Range
Abstract In this paper we have presented the four new investigations using different structures of Photonic Crystal Fiber (PCF) for broadband communication applications and narrows down on the design which can provide largest flat negative dispersion. The new structure model is optimized based on the combination of modal properties and dispersion compensatio
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-12
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12. Comparison of the marginal adaptation of direct and indirect composite inlay restorations with optical coherence tomography
ABSTRACT Objective The purpose of the study was to use the photonic imaging modality of optical coherence tomography (OCT) to compare the marginal adaptation of composite inlays fabricated by direct and indirect techniques. Material and Methods Class II cavities were prepared on 34 extracted human molar teeth. The cavities were randomly divided into two
J. Appl. Oral Sci.. Publicado em: 2016-08