The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Yasuhide Tsuji - One of the best experts on this subject based on the ideXlab platform.

  • design of cross talk free polarization converter based on square lattice Elliptical Hole core circular Hole Holey fibers
    Journal of The Optical Society of America B-optical Physics, 2016
    Co-Authors: Zejun Zhang, Yasuhide Tsuji, Masashi Eguchi
    Abstract:

    In this paper, a novel polarization converter (PC) based on square-lattice Elliptical-Hole core circular-Hole Holey fibers is proposed and analyzed. The proposed PC has oblique Elliptical air Holes in the core region, which can achieve polarization rotation with a conversion length as short as 31.7 μm. Additionally, in order to achieve a cross-talk-free PC element, we propose a PC element with three cores, which can completely convert polarization state by 90 deg. The structural tolerance of the cross-talk-free PC element has also been discussed in detail.

  • study on crosstalk free polarization splitter with Elliptical Hole core circular Hole Holey fibers
    Journal of Lightwave Technology, 2014
    Co-Authors: Zejun Zhang, Yasuhide Tsuji, Masashi Eguchi
    Abstract:

    We proposed a novel polarization splitter based on single-polarized Elliptical-Hole core circular-Hole Holey fibers (EC-CHFs). We employed the full-vector finite element beam propagation method to demonstrate the polarization splitter which is designed by the large Hole EC-CHFs (air filling fraction in core is 36.73%) and small Hole EC-CHFs (air filling fraction in core is 4.08%) can completely split an arbitrarily polarized light beam into two orthogonal polarization states without any crosstalk. In addition, we also calculated the tolerance and wavelength dependence of this kind of polarization splitter.

  • design of polarization splitter with single polarized Elliptical Hole core circular Hole Holey fibers
    IEEE Photonics Technology Letters, 2014
    Co-Authors: Zejun Zhang, Yasuhide Tsuji, Masashi Eguchi
    Abstract:

    We propose a novel polarization splitter based on coupled Elliptical-Hole core circular-Hole Holey fibers (EC-CHFs). Utilizing the single-polarization nature of the EC-CHFs, in the proposed polarization splitter, two orthogonally polarized waves couple only to different EC-CHFs and the crosstalk-free polarization splitting is realized. In addition, the coupling length for two orthogonally polarized waves can be independently designed and this splitter is easy to design.

  • influence of reflected radiation waves caused by large mode field and large refractive index mismatches on splice loss evaluation between Elliptical Hole lattice core Holey fibers and conventional fibers
    Journal of The Optical Society of America B-optical Physics, 2013
    Co-Authors: Masashi Eguchi, Yasuhide Tsuji
    Abstract:

    When the mode field and refractive index mismatches between two spliced fibers are small, the splice loss is generally evaluated by calculating an overlap integral without reflection waves. A single-polarization circular-Hole Holey fiber with a core consisting of an Elliptical-Hole lattice (EC-CHF) has a strikingly different mode field caused by Elliptical Holes in the core region from those of conventional single-mode fibers (SMFs), and thus reflected radiation modes may significantly appear in splicing an EC-CHF to conventional SMFs. We study the influence of reflected radiation modes on the splice loss evaluation of optical fibers with large mode field and large refractive index mismatches through numerical analyses using a bidirectional eigenmode propagation method and a three-dimensional finite-element method.

  • single polarization Elliptical Hole lattice core photonic bandgap fiber
    Journal of Lightwave Technology, 2013
    Co-Authors: Masashi Eguchi, Yasuhide Tsuji
    Abstract:

    In photonic bandgap (PBG) fibers, light is confined by a photonic bandgap caused by a periodic structure of air Holes in the cladding regions. The doubly degenerate fundamental mode in ideal PBG fiber structures becomes slightly nondegenerate in actually produced fibers, and this causes polarization instability and polarization mode dispersion. Here, to avoid these problems, we propose a novel absolutely single-polarization PBG fiber structure with an Elliptical-Hole lattice core. A PBG fiber with a single-polarization bandwidth of 420 nm is numerically demonstrated. Furthermore, based on the proposed fiber structure, we report another single-polarization PBG fiber that has two absolutely single-polarization bands being orthogonal to each other.

Masashi Eguchi - One of the best experts on this subject based on the ideXlab platform.

  • design of cross talk free polarization converter based on square lattice Elliptical Hole core circular Hole Holey fibers
    Journal of The Optical Society of America B-optical Physics, 2016
    Co-Authors: Zejun Zhang, Yasuhide Tsuji, Masashi Eguchi
    Abstract:

    In this paper, a novel polarization converter (PC) based on square-lattice Elliptical-Hole core circular-Hole Holey fibers is proposed and analyzed. The proposed PC has oblique Elliptical air Holes in the core region, which can achieve polarization rotation with a conversion length as short as 31.7 μm. Additionally, in order to achieve a cross-talk-free PC element, we propose a PC element with three cores, which can completely convert polarization state by 90 deg. The structural tolerance of the cross-talk-free PC element has also been discussed in detail.

  • study on crosstalk free polarization splitter with Elliptical Hole core circular Hole Holey fibers
    Journal of Lightwave Technology, 2014
    Co-Authors: Zejun Zhang, Yasuhide Tsuji, Masashi Eguchi
    Abstract:

    We proposed a novel polarization splitter based on single-polarized Elliptical-Hole core circular-Hole Holey fibers (EC-CHFs). We employed the full-vector finite element beam propagation method to demonstrate the polarization splitter which is designed by the large Hole EC-CHFs (air filling fraction in core is 36.73%) and small Hole EC-CHFs (air filling fraction in core is 4.08%) can completely split an arbitrarily polarized light beam into two orthogonal polarization states without any crosstalk. In addition, we also calculated the tolerance and wavelength dependence of this kind of polarization splitter.

  • design of polarization splitter with single polarized Elliptical Hole core circular Hole Holey fibers
    IEEE Photonics Technology Letters, 2014
    Co-Authors: Zejun Zhang, Yasuhide Tsuji, Masashi Eguchi
    Abstract:

    We propose a novel polarization splitter based on coupled Elliptical-Hole core circular-Hole Holey fibers (EC-CHFs). Utilizing the single-polarization nature of the EC-CHFs, in the proposed polarization splitter, two orthogonally polarized waves couple only to different EC-CHFs and the crosstalk-free polarization splitting is realized. In addition, the coupling length for two orthogonally polarized waves can be independently designed and this splitter is easy to design.

  • influence of reflected radiation waves caused by large mode field and large refractive index mismatches on splice loss evaluation between Elliptical Hole lattice core Holey fibers and conventional fibers
    Journal of The Optical Society of America B-optical Physics, 2013
    Co-Authors: Masashi Eguchi, Yasuhide Tsuji
    Abstract:

    When the mode field and refractive index mismatches between two spliced fibers are small, the splice loss is generally evaluated by calculating an overlap integral without reflection waves. A single-polarization circular-Hole Holey fiber with a core consisting of an Elliptical-Hole lattice (EC-CHF) has a strikingly different mode field caused by Elliptical Holes in the core region from those of conventional single-mode fibers (SMFs), and thus reflected radiation modes may significantly appear in splicing an EC-CHF to conventional SMFs. We study the influence of reflected radiation modes on the splice loss evaluation of optical fibers with large mode field and large refractive index mismatches through numerical analyses using a bidirectional eigenmode propagation method and a three-dimensional finite-element method.

  • single polarization Elliptical Hole lattice core photonic bandgap fiber
    Journal of Lightwave Technology, 2013
    Co-Authors: Masashi Eguchi, Yasuhide Tsuji
    Abstract:

    In photonic bandgap (PBG) fibers, light is confined by a photonic bandgap caused by a periodic structure of air Holes in the cladding regions. The doubly degenerate fundamental mode in ideal PBG fiber structures becomes slightly nondegenerate in actually produced fibers, and this causes polarization instability and polarization mode dispersion. Here, to avoid these problems, we propose a novel absolutely single-polarization PBG fiber structure with an Elliptical-Hole lattice core. A PBG fiber with a single-polarization bandwidth of 420 nm is numerically demonstrated. Furthermore, based on the proposed fiber structure, we report another single-polarization PBG fiber that has two absolutely single-polarization bands being orthogonal to each other.

Norio Hasebe - One of the best experts on this subject based on the ideXlab platform.

  • Magneto-elastic stress induced by an electric current in an infinite thin plate with an Elliptical Hole
    Archive of Applied Mechanics, 2010
    Co-Authors: Norio Hasebe
    Abstract:

    Two-dimensional magnetic field and stress analyses have been presented for soft ferromagnetic, paramagnetic, and diamagnetic materials of an infinite thin plate with an Elliptical Hole under steady electric current. The magnetic stress has been analyzed in the Maxwell Stress Model. Except for the approximation of the plane stress state since the plate is the thin plate, any assumption is not made for the stress analysis, though the Maxwell stress components are expressed by nonlinear terms. The boundary condition expressed by Maxwell’s stress is completely satisfied without any linear assumptions on the boundary. Two ways for the boundary condition are stated. The analysis of σ _ z in the direction of the plate thickness is also carried out. Figures of the magnetic field and stress distribution are shown. Stress intensity factors are also derived, and the magnitude of the stress intensity factor for the magnetic stress and thermal stress due to the Joule heat caused by the electric current is discussed.

  • heat conduction and thermal stress induced by an electric current in an infinite thin plate containing an Elliptical Hole with an edge crack
    International Journal of Solids and Structures, 2010
    Co-Authors: Norio Hasebe, Christian Bucher, R Heuer
    Abstract:

    Abstract A uniform electric current at infinity was applied to a thin infinite conductor containing an Elliptical Hole with an edge crack. The electric current gives rise to two states, i.e., uniform and uneven Joule heat. These two states must be considered to analyze the heat conduction problem. The uneven Joule heat gives rise to uneven temperature and thus to heat flux, and to thermal stress. Using a rational mapping function, problems of the electric current, the Joule heat, the temperature, the heat flux, the thermal stress are analyzed, and each of their solutions is obtained as a closed form. The distributions of the electric current, the Joule heat, the temperature, the heat flux and the stress are shown in figures. The heat conduction problem is solved as a temperature boundary value problem. Solving the thermal stress problem, dislocation and rotation terms appear, which complicates this problem. The solutions of the Joule heat, the temperature, the heat flux and the thermal stress are nonlinear in the direction of the electric current. The crack problems are also analyzed, and the singular intensities at the crack tip of each problem are obtained. Mode II (sliding mode) stress intensity factor (SIF) is produced as well as Mode I (opening mode) SIF, for any direction of the electric current. The relations between the electric current density and the melting temperature and between the electric current density and SIF are investigated for some crack lengths in an aluminum plate.

  • analyses of thermal conduction and stress induced by electric current in an infinite thin plate with an Elliptical Hole
    Journal of Thermal Stresses, 2009
    Co-Authors: Norio Hasebe, Christian Bucher, R Heuer
    Abstract:

    Uniform electric current at infinity is applied to a thin infinite conductor with an Elliptical Hole disturbing the electric current, which gives rise to Joule heat, temperature increase and heat flux. Joule heat produces uniform and uneven temperature fields which in turn initiate thermal stress. These electrical current, Joule heat, temperature, heat flux and thermal stress analyses are carried out and their closed form solutions are obtained. The heat conduction problem is solved as a temperature boundary value problem. Figures of distribution of Joule heat, temperature, heat flux and stress are shown. A dislocation and a rotation terms for thermal stress analysis appear, which makes problem complex. Solutions of Joule heat, temperature, heat flux and thermal stress are nonlinear for the direction of electric current. For an infinite plate with a circular Hole, stress components do not occur on the wHole plate. As a special case, a crack problem is analyzed and intensities at the crack tip of each prob...

  • anti plane shear stress problem of two bonded dissimilar half spaces with an Elliptical Hole or rigid inclusion on the interface
    Acta Mechanica, 2009
    Co-Authors: Norio Hasebe, Leon M Keer
    Abstract:

    The problem of anti-plane shear stress of two bonded dissimilar half spaces with an Elliptical Hole or a rigid inclusion at the interface and having interfacial cracks is presented. Uniform anti-plane shear stresses and the stress free or zero displacement boundary conditions on the Elliptical Hole are considered. The two cases are reduced to Riemann–Hilbert problems and closed form solutions are obtained by use of the complex stress function and the conformal mapping approaches. Stress distributions, as well as stress intensity factor, are shown. When the Elliptical Hole collapses, the known solutions of the interfacial crack and thin rigid fiber can be obtained. If the coordinates in the Plemelj function are changed, a debonding length can be determined.

  • electromagnetic fields induced by electric current in an infinite plate with an Elliptical Hole
    Quarterly Journal of Mechanics and Applied Mathematics, 2008
    Co-Authors: Norio Hasebe, Leon M Keer, Qian Wang
    Abstract:

    Analytical solutions to the electromagnetic field in a thin conductive plate with an Elliptical Hole are derived by means of complex potentials and conformal mapping techniques. The steady-state current field in a thin conductive plate is two dimensional (2D) and is explored by a standard complex variable technique. The current is disturbed around the Elliptical Hole, and produces a three dimensional magnetic field. In this case, using the complex variable method to solve the real magnetic field can be challenging. The magnetic boundary conditions take different forms for the soft ferromagnetic and the para- or diamagnetic materials under consideration. A simplified analysis taking account of the magnitude of the magnetic permeability of the magnetic material and air surrounding the material is proposed to reduce the magnetic field in a thin plate to 2D calculations. The magnetic field distributions are derived for each material and the equations of the magnetic components at the tip of Elliptical Hole are presented.

Peter Schiavone - One of the best experts on this subject based on the ideXlab platform.

  • stress concentration around an Elliptical Hole with surface tension based on the original gurtin murdoch model
    Mechanics of Materials, 2019
    Co-Authors: Ming Dai, Haibing Yang, Peter Schiavone
    Abstract:

    Abstract It is widely appreciated that surface tension plays a central role in the mechanics of soft solids such as gels. The original Gurtin–Murdoch (G–M) surface model incorporated the contribution of surface tension also via the dependence of surface stress on surface deformation. In many subsequent researches, this contribution was neglected presumably to simplify the analysis of the corresponding models of deformation. Here, we restore the original G–M surface model and re-examine the problem of an Elliptical Hole with a constant surface tension in an elastic infinite plane under a uniform remote in-plane loading. Semi-analytic solutions for the full stress field are derived based on series expansion techniques. Numerical examples are presented to compare the original G–M model with its simplified counterpart (which neglects the deformation-induced change in the configuration of the Hole) in predicting the hoop stress around the Hole. We show that in the absence of remote loading the use of the simplified G–M model generally overestimates the surface tension-induced residual hoop stress around the Hole especially when the Hole is slender. In the context of the original G–M model, we find that the presence of surface tension may intensify the remote loading-induced hoop stress concentration significantly at the endpoints of the Hole's major axis as the Hole becomes slender (for example, in the case of a remote tensile loading perpendicular to the major axis of the Hole), which certainly does not happen for the simplified G–M model.

  • surface tension induced stress concentration around an Elliptical Hole in an anisotropic half plane
    Mechanics Research Communications, 2016
    Co-Authors: Ming Dai, Peter Schiavone, Cun-fa Gao
    Abstract:

    Abstract We examine the surface tension-induced stress concentration around an Elliptical Hole inside an anisotropic half-plane with traction-free surface. Using conformal mapping techniques, the corresponding complex potential in the half-plane is expressed in a series whose unknown coefficients are determined numerically. Our results indicate that the maximum hoop stress around the Hole (which appears in the vicinity of the point of maximum curvature) increases rapidly with decreasing distance between the Hole and the free surface. In particular, for an Elliptical or even circular Hole in an anisotropic half-plane we find that, with decreasing distance between the Hole and the free surface, the hoop stress can switch from compressive to tensile at certain points on the Hole's boundary and from tensile to compressive at others. This phenomenon is absent in the case of an Elliptical or even circular Hole in the corresponding case of an isotropic half-plane.

  • Deformations near an Elliptical Hole with surface effect in a laminated anisotropic thin plate
    ZAMM - Journal of Applied Mathematics and Mechanics Zeitschrift für Angewandte Mathematik und Mechanik, 2015
    Co-Authors: Xu Wang, Peter Schiavone
    Abstract:

    This work is concerned with the coupled stretching and bending deformation around an Elliptical Hole with surface energy in a laminated and inhomogeneous anisotropic elastic thin plate within the context of the Kirchhoff theory. A closed-form full-field solution is derived by using the octet formalism recently developed by Cheng and Reddy (2002, 2003, 2004, 2005) and by incorporating a simplified version of the surface elasticity model. In particular, explicit real-form expressions of the hoop membrane stress resultant, hoop bending moment, in-plane displacements and slopes on the mid-plane along the edge of the Elliptical Hole are obtained.

  • surface effects in the deformation of an anisotropic elastic material with nano sized Elliptical Hole
    Mechanics Research Communications, 2013
    Co-Authors: Xu Wang, Peter Schiavone
    Abstract:

    Abstract We examine the effect of surface energy on an anisotropic elastic material weakened by an Elliptical Hole. A closed-form, full-field solution is derived using the standard Stroh formalism. In particular, explicit expressions for the hoop stress, normal, in-plane tangential and out-of-plane displacement components along the edge of the Hole are obtained. These expressions clearly demonstrate the effect of elastic anisotropy of the bulk material on the corresponding field variables. When the material becomes isotropic, the hoop stress agrees with the well-known result in the literature while both the in-plane tangential and out-of-plane displacements vanish and the normal displacement is constant along the entire boundary of the Elliptical Hole.

  • role of surface effects in the finite deformation of an elastic solid with Elliptical Hole
    International Journal of Non-linear Mechanics, 2013
    Co-Authors: Xu Wang, Peter Schiavone
    Abstract:

    We study the finite plane deformations of a particular harmonic material surrounding an Elliptical Hole whose boundary incorporates the contribution of surface mechanics. We are particularly interested in the distribution of the Piola hoop stress along the edge of the Hole. Surprisingly, in the absence of any external loading, the hoop stress induced solely by the surface effects is identical to that in the corresponding case in a linearly elastic solid. In addition, we show that even in the presence of surface effects, we can nevertheless design a so-called ‘harmonic Hole’ where the Piola mean stress remains constant everywhere in the surrounding solid. In this case, however, the hoop stress is no longer constant along the edge of the Elliptical Hole due to the contribution from surface energy.

Zejun Zhang - One of the best experts on this subject based on the ideXlab platform.