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On dispersion relations in smart laminated fiber-reinforced composite membranes considering different piezoelectric coupling effects
摘要： Wave propagation characteristics are determined for smart laminated fiber-reinforced composite cylindrical membrane shells with different piezoelectric coupling effects. Wave motion equations are derived using the membrane shell model. By solving an eigenvalue problem, dispersion curves of the wave motion are obtained for different axial and circumferential wave numbers. The effects of piezoelectric coupling, fiber orientation, stacking sequence, and material properties of the host shell on wave behaviors are investigated. The results of this paper can be used for studies on dynamic stability of piezoelectric coupled laminated fiber-reinforced composite shell structures and in design of smart structures with the piezoelectric materials for the applications of damage detection and structural health monitoring.
关键词： dispersion,piezoelectric,Composite,wave propagation,membrane shell
更新于2025-09-19 17:15:36
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Retrieving effective material parameters of metamaterials characterized by nonlocal constitutive relations
摘要： The parameter retrieval is a procedure in which effective material properties are assigned to a given metamaterial. A widely used technique bases on the inversion of reflection and transmission from a metamaterial slab. Thus far, local constitutive relations have been frequently considered in this retrieval procedure to describe the metamaterial at the effective level. This, however, is insufficient. The retrieved local material properties frequently fail to predict reliably the optical response from the slab in situations that deviate from those that have been considered in the retrieval, e.g., when illuminating the slab at a different incidence angle. To significantly improve the situation, we describe here a parameter retrieval, also based on the inversion of reflection and transmission from a slab, that describes the metamaterial at the effective level with nonlocal constitutive relations. We retrieve the effective material parameters at the example of a basic metamaterial, namely, dielectric spheres on a cubic lattice but also on a more advanced, anisotropic metamaterial of current interest, i.e., the fishnet metamaterial. We demonstrate that the nonlocal constitutive relation can describe the optical response much better than local constitutive relation would do. Our approach is widely applicable to a large class of metamaterials.
关键词： nonlocal constitutive relations,spatial dispersion,parameter retrieval,metamaterials,homogenization
更新于2025-09-19 17:15:36
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A combined experimental and theoretical study of optical rotatory dispersion for ( <i>R</i> )-glycidyl methyl ether in aqueous solution
摘要： The dispersive optical activity for aqueous solutions of non-rigid (R)-glycidyl methyl ether (R-GME) has been explored synergistically from experimental and theoretical perspectives. Density functional theory analyses performed with the polarizable continuum model for implicit solvation identified nine low-lying stable conformers that are interconverted by rotation about two large-amplitude torsional coordinates. The antagonistic chiroptical signatures predicted for these structural isomers were averaged under a Boltzmann-weighting ansatz to estimate the behavior expected for a thermally equilibrated ensemble. This led to optical rotatory dispersion profiles that reproduced the overall shape of observations but failed to achieve uniform agreement with measured specific-rotation values even when anharmonic vibrational corrections were applied. A mixed QM/FQ paradigm, whereby quantum-mechanical (QM) calculations of optical activity were combined with classical molecular dynamics simulations of explicit solvation that included mutual-polarization effects by means of fluctuating charges (FQ), was enlisted to elucidate the microsolvation environment and gauge its impact upon conformer distributions and response properties. Although quantitative accord with experiments remained elusive, this approach revealed strong variations in the magnitude and sign of rotatory powers for R-GME as the configuration of surrounding water molecules evolved, thereby highlighting the inherently dynamical nature of the solvated chiroptical response, calling into question the validity of ''static'' descriptions based on the presumption of distinct energy minima, and giving insight into the inherent complexity posed by the modeling of such properties for solvated systems.
关键词： aqueous solution,fluctuating charges,molecular dynamics,(R)-glycidyl methyl ether,chiroptical properties,polarizable continuum model,optical rotatory dispersion,density functional theory
更新于2025-09-19 17:15:36
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Multiple embedded eigenstates in nonlocal plasmonic nanostructures
摘要： Trapping light in open cavities is a long sought “holy grail” of nanophotonics. Plasmonic materials may offer a unique opportunity in this context, as they may fully suppress the radiation loss and enable the observation of spatially localized light states with an infinite lifetime in an open system. Here, we investigate how the spatial dispersion effects, e.g., caused by the electron-electron interactions in a metal, affect the trapped eigenstates. Heuristically, one may expect that the repulsive-type electron-electron interactions should act against light localization, and thereby that they should have a negative impact on the formation of the embedded eigenstates. Surprisingly, here we find that the nonlocality of the material response creates new degrees of freedom and relaxes the requirements for the observation of trapped light. In particular, a zero-permittivity condition is no longer mandatory and the same resonator shell can potentially suppress the radiation loss at multiple frequencies.
关键词： spatial dispersion,nonlocal plasmonic nanostructures,light trapping,embedded eigenstates
更新于2025-09-19 17:13:59
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Unidirectional and robust propagating surface magnetoplasmon in magneto-optical coaxial waveguides
摘要： In this paper, a novel coaxial waveguide constituted by a hollow cylinder made of a magneto-optical material and a metal wire at the axis is proposed. The surface magnetoplasmon and guided modes of the waveguide are studied. The results show that the dispersion relation and electromagnetic field distribution are highly sensitive to the operating frequency and physical dimensions of the structure. It is demonstrated that there exist three different types of modes, that is bulk-mode, surface mode, and regular mode. By adjusting the operating frequency and reducing the inner diameter of the hollow cylinder, the regular mode is suppressed and only the surface mode remains, which shows one-way propagating property. Moreover, the one-way surface mode is robust against backscattering at defect and surface roughness, which has a good potential in practice. The unique properties of this waveguide are demonstrated through mode analyses as well as numerical simulations.
关键词： electromagnetic field distribution,dispersion relation,surface magnetoplasmon,one-way propagation,magneto-optical coaxial waveguides
更新于2025-09-19 17:13:59
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Waveguide-induced dispersion interaction between two two-level atoms with orthogonal in-transverse-plane dipoles
摘要： We study the dispersion interaction between two ground-state two-level atoms near a cylindrical vacuum-clad optical waveguide. We focus on the case where the electric-dipole matrix-element vectors of the atoms are perpendicular to each other and to the interatomic axis. When these atoms are in free space, the dispersion interaction between them vanishes. In the presence of a waveguide aligned parallel to the interatomic axis, the energy of the dispersion interaction between the atoms may become nonzero and comparable to the average energy of the dispersion interaction between two atoms with arbitrarily oriented dipoles in free space. This waveguide-induced dispersion interaction is a consequence of the anisotropy of the medium around the atoms.
关键词： waveguide,anisotropy,two-level atoms,dispersion interaction
更新于2025-09-19 17:13:59
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Dissipative soliton resonance in a simple linear cavity Tm3+-doped double clad fiber laser with dispersion management
摘要： We report on the investigation of large energy dissipative soliton resonance (DSR) pulse generation in a simple linear cavity Tm3+-doped fiber laser (TDFL), by using semiconductor saturable absorption mirror (SESAM) as saturable absorber (SA). This DSR TDFL is implemented by utilizing ultra-high numerical aperture 4 (UHNA4) fiber for dispersion compensation. With further dispersion management, the DSR TDFL can generate an average output power of 242 mW with corresponding pulse energy of ~61 nJ. Moreover, the soliton molecules mode-locked operation has also been demonstrated in this TDFL. Our results can provide an easily accessible way to develop large energy TDFLs.
关键词： dispersion management,Tm3+-doped fiber laser,semiconductor saturable absorption mirror,dissipative soliton resonance
更新于2025-09-19 17:13:59
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Time-frequency analysis of laser-excited surface acoustic waves based on synchrosqueezing transform
摘要： Laser-excited surface acoustic wave (LSAW) techniques can realize the measurement of surface properties through dispersion curve inversion. In addition to the conventional phase spectrum method, time-frequency analysis can also be used as a calculation tool for the dispersion curve. An accurate time-frequency analysis method is important in precisely inverting the surface properties. In this paper, synchrosqueezing transform (SST) is applied to the analysis of LSAW. By comparing the processing results of the constructed LSAW signal, SST shows higher time-frequency resolution and robustness than other common time-frequency analysis algorithms. Finite element model is used to simulate the propagation of LSAW in the film/substrate structure. And SST is used to calculate the dispersion curve of SAW information extracted during the simulation. A fast algorithm is introduced, where the film thickness is initially estimated by calculating the midrange. Through inversion, the resulting film thickness error is only 1.20% from the theoretical value. Therefore, SST is an effective tool for analyzing LSAW and calculating its dispersion curve.
关键词： Synchrosqueezing transform,Surface acoustic wave,Surface properties,Dispersion curve
更新于2025-09-19 17:13:59
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Spoof plasmonic metasurfaces with catenary dispersion for two-dimensional wide-angle focusing and imaging
摘要： Despite tremendous efforts have been devoted to investigating the analogy between the surface plasmon polariton and its spoof counterparts, it remains elusive that a single thin spoof plasmonic metalens realize wide-angle focusing and wide field-of-view (FOV) imaging. Here, we propose a spoof plasmonic metasurface that can impart arbitrary phase with high transmittance, which is comprised of two-dimensional (2D) gradient spoof-insulator-spoof waveguides. With the developed catenary field and dispersion theory, their intrinsic physics are theoretically analyzed. As a proof of concept, a spoof plasmonic metalens with a thickness of 0.15λ has been elaborately designed and experimentally demonstrated for wide-angle (~170°) focusing and wide FOV (~40°) imaging. To the best of our knowledge, it is the first experimental demonstration of wide FOV imaging of a 2D object with single thin and planar metalens in the microwave regime. The proposed method offers a promising solution to compact cameras, integrated imaging, and detection systems.
关键词： catenary dispersion,microwave regime,spoof plasmonic metasurfaces,wide-angle focusing,wide FOV imaging
更新于2025-09-19 17:13:59
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Thermally Stable Aua??BaTiO <sub/>3</sub> Nanoscale Hybrid Metamaterial for High-Temperature Plasmonic Applications
摘要： The thermal stability of the Au?BaTiO3 nanocomposite thin film as a hybrid metamaterial deposited by a one-step pulsed laser deposition (PLD) method has been investigated via both ex situ annealing followed by TEM analysis and an in situ heating study in TEM. For the ex situ annealing study, the XRD analysis shows good crystallinity for both as-deposited and annealed films after being annealed at 600 °C for different time periods (i.e. 1, 3, 6, and 30 hours). The optical measurements including transmittance/reflectance, ellipsometry, and Raman spectroscopy demonstrate excellent optical properties of the hybrid metamaterial films by exhibiting the static localized surface plasmon resonance (LSPR) peak and hyperbolic dispersion in the visible to near-infrared regime. Both TEM results of the ex situ annealed samples and in situ heating TEM results reveal no obvious microstructure change after the extensive high-temperature annealing and suggest the high thermal stability of the Au?oxide hybrid materials for their future high-temperature plasmonic applications.
关键词： crystallinity,localized surface plasmon resonance,in situ,hyperbolic dispersion,hybrid metamaterial,thermal stability,ex situ
更新于2025-09-19 17:13:59