The Experts below are selected from a list of 50010 Experts worldwide ranked by ideXlab platform
Masanori Koshiba - One of the best experts on this subject based on the ideXlab platform.
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A Wide-Angle Finite~:element Beam Propagation ' ¥¢thod
2016Co-Authors: Masanori Koshiba, Senior Member, Yasuhide TsujiAbstract:Abstract- A wide-angle finite-element Beam Propagation method based on the Pade approximation is developed. Considerable improvement in accuracy over the paraxial approximation is achieved with virtually no additiomil computation. In the present algorithm, the quadratic element, transparent boundary condition, adaptive reference index, and adaptive grid are effectively UTILIZED. 1
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full vectorial finite element Beam Propagation method with perfectly matched layers for anisotropic optical waveguides
Journal of Lightwave Technology, 2001Co-Authors: Kunimasa Saitoh, Masanori KoshibaAbstract:Perfectly matched layer (PML) boundary conditions are incorporated into the full-vectorial Beam Propagation method (BPM) based on a finite element scheme for the three-dimensional (3-D) anisotropic optical waveguide analysis. In the present approach, edge elements based on linear-tangential and quadratic-normal vector basis functions are used for the transverse field components. To show the validity and usefulness of this approach, numerical examples are shown for Gaussian Beam Propagation in proton-exchanged LiNbO/sub 3/ optical waveguides. Numerical accuracy of the present PML boundary condition is investigated in detail by comparing the results with those of the conventional absorbing boundary condition (ABC).
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guided mode and leaky mode analysis by imaginary distance Beam Propagation method based on finite element scheme
Journal of Lightwave Technology, 2000Co-Authors: Yasuhide Tsuji, Masanori KoshibaAbstract:As a simple analysis method to solve eigenmodes of optical waveguides, we present an imaginary distance Beam Propagation method (BPM) based on finite element scheme. The matrices used in the Beam Propagation analysis are essentially complex, so lossy optical waveguides can be easily treated. Moreover, employing the transparent boundary condition or perfectly matched layer boundary condition, the validity of a which has been already confirmed in the real distance BPM, we can easily treat not only guided modes but leaky ones. To show the validity and usefulness of this approach, eigenmodes of twoand three-dimensional leaky waveguides, and optical fibers are calculated.
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time domain Beam Propagation method and its application to photonic crystal circuits
Journal of Lightwave Technology, 2000Co-Authors: Masanori Koshiba, Yasuhide Tsuji, M HikariAbstract:A time-domain Beam Propagation method (BPM) based on the finite-element scheme is described for the analysis of reflections of both transverse electric and transverse magnetic polarized pulses in waveguiding structures containing arbitrarily shaped discontinuities. In order to avoid nonphysical reflections from the computational window edges, the perfectly matched layer boundary condition is introduced. The present algorithm using the Pade approximation is, to our knowledge, the first time-domain Beam Propagation method which can treat wide-band optical pulses. After validating this method for an optical grating with modulated refractive indexes, various photonic crystal circuit components are simulated.
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a wide angle Beam Propagation method based on a finite element scheme
IEEE Transactions on Magnetics, 1997Co-Authors: Yasuhide Tsuji, Masanori Koshiba, Tomohide TanabeAbstract:A wide-angle finite element Beam Propagation method using a Pade approximant operator is described for strongly guiding and longitudinally varying optical waveguides. In order to show the validity and robustness of this approach, numerical results are compared with those of other Beam Propagation algorithms.
Yasuhide Tsuji - One of the best experts on this subject based on the ideXlab platform.
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A Wide-Angle Finite~:element Beam Propagation ' ¥¢thod
2016Co-Authors: Masanori Koshiba, Senior Member, Yasuhide TsujiAbstract:Abstract- A wide-angle finite-element Beam Propagation method based on the Pade approximation is developed. Considerable improvement in accuracy over the paraxial approximation is achieved with virtually no additiomil computation. In the present algorithm, the quadratic element, transparent boundary condition, adaptive reference index, and adaptive grid are effectively UTILIZED. 1
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guided mode and leaky mode analysis by imaginary distance Beam Propagation method based on finite element scheme
Journal of Lightwave Technology, 2000Co-Authors: Yasuhide Tsuji, Masanori KoshibaAbstract:As a simple analysis method to solve eigenmodes of optical waveguides, we present an imaginary distance Beam Propagation method (BPM) based on finite element scheme. The matrices used in the Beam Propagation analysis are essentially complex, so lossy optical waveguides can be easily treated. Moreover, employing the transparent boundary condition or perfectly matched layer boundary condition, the validity of a which has been already confirmed in the real distance BPM, we can easily treat not only guided modes but leaky ones. To show the validity and usefulness of this approach, eigenmodes of twoand three-dimensional leaky waveguides, and optical fibers are calculated.
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time domain Beam Propagation method and its application to photonic crystal circuits
Journal of Lightwave Technology, 2000Co-Authors: Masanori Koshiba, Yasuhide Tsuji, M HikariAbstract:A time-domain Beam Propagation method (BPM) based on the finite-element scheme is described for the analysis of reflections of both transverse electric and transverse magnetic polarized pulses in waveguiding structures containing arbitrarily shaped discontinuities. In order to avoid nonphysical reflections from the computational window edges, the perfectly matched layer boundary condition is introduced. The present algorithm using the Pade approximation is, to our knowledge, the first time-domain Beam Propagation method which can treat wide-band optical pulses. After validating this method for an optical grating with modulated refractive indexes, various photonic crystal circuit components are simulated.
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a wide angle Beam Propagation method based on a finite element scheme
IEEE Transactions on Magnetics, 1997Co-Authors: Yasuhide Tsuji, Masanori Koshiba, Tomohide TanabeAbstract:A wide-angle finite element Beam Propagation method using a Pade approximant operator is described for strongly guiding and longitudinally varying optical waveguides. In order to show the validity and robustness of this approach, numerical results are compared with those of other Beam Propagation algorithms.
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A wide-angle finite-element Beam Propagation method
IEEE Photonics Technology Letters, 1996Co-Authors: Masanori Koshiba, Yasuhide TsujiAbstract:A wide-angle finite-element Beam Propagation method based on the Pade approximation is developed. Considerable improvement in accuracy over the paraxial approximation is achieved with virtually no additional computation. In the present algorithm, the quadratic element, transparent boundary condition, adaptive reference index, and adaptive grid are effectively utilized.
Peter Bienstman - One of the best experts on this subject based on the ideXlab platform.
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application of modified pade approximant operators to time domain Beam Propagation methods
Journal of The Optical Society of America B-optical Physics, 2009Co-Authors: T M Benson, Peter BienstmanAbstract:We demonstrate the usefulness of the recently introduced modified Pade approximant operators for the solution of time-domain Beam Propagation problems. We show this both for a wideband method, which can take reflections into account, and for a split-step method for the modeling of ultrashort unidirectional pulses. The resulting approaches achieve high-order accuracy not only in space but also in time.
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non paraxial Beam Propagation in nonlinear optical waveguides using complex jacobi iteration
International Conference on Numerical Simulation of Optoelectronic Devices, 2009Co-Authors: Peter BienstmanAbstract:We present the recently introduced Beam Propagation method using complex Jacobi iteration adapted for efficient modeling of non-paraxial Beam Propagation in nonlinear optical waveguides.
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fast three dimensional generalized rectangular wide angle Beam Propagation method using complex jacobi iteration
Journal of The Optical Society of America B-optical Physics, 2009Co-Authors: Peter BienstmanAbstract:A fast and efficient three-dimensional generalized rectangular wide-angle Beam Propagation method (GR-WA-BPM) based on a recently proposed modified Pade (1,1) approximant is presented. In our method, at each Propagation step, the Beam Propagation equation is recast in terms of a Helmholtz equation with a source term, which is solved quickly and accurately by a recently introduced complex Jacobi iterative (CJI) method. The efficiency of the GR-WA-BPM for the analysis of tilted optical waveguides is demonstrated in comparison with the standard wide-angle Beam Propagation method based on Hadley's scheme. In addition, since the utility of the CJI method depends mostly on its execution speed in comparison with the traditional direct matrix inversion, several performance comparisons are also presented.
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wide angle Beam Propagation method without using slowly varying envelope approximation
Journal of The Optical Society of America B-optical Physics, 2009Co-Authors: Peter BienstmanAbstract:A new wide-angle (WA) Beam Propagation method (BPM) is developed whereby the exact scalar Helmholtz propagator is replaced by any one of a sequence of higher-order (m,n) Pade approximant operators. Unlike the previous well-known WA-BPM proposed by Hadley [Opt. Lett.17, 1426 (1992)], the resulting formulations allow one a direct solution of the second-order scalar wave equation without having to make slowly varying envelope approximations so that the WA formulations are completely general. The accuracy and improvement of this approximate calculation of the propagator is demonstrated in comparison with the exact result and existing approximate approaches. The method is employed to simulate two-dimensional (2D) and three-dimensional (3D) optical waveguides and compared with the results obtained by the existing approach.
Wei-ping Huang - One of the best experts on this subject based on the ideXlab platform.
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wide angle Beam Propagation method based on high accuracy finite difference formulas
Integrated Photonics Research and Applications Nanophotonics (2006) paper ITuA2, 2006Co-Authors: Hua Zhang, Wei-ping Huang, Ningning FengAbstract:It is demonstrated that the wide-angle Beam Propagation method based on the fourth-order finite-difference formula can provide accurate results for strongly guiding waveguides even with coarse grids, while keeping high efficiency.
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the perfectly matched layer pml boundary condition for the Beam Propagation method
IEEE Photonics Technology Letters, 1996Co-Authors: Wei-ping Huang, W Lui, Kiyoyuki YokoyamaAbstract:The perfectly matched layer (PML) boundary condition for the Helmoltz equation is developed and applied to the finite-difference Beam Propagation method. Its effectiveness is verified by way of examples.
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a wide angle vector Beam Propagation method
IEEE Photonics Technology Letters, 1992Co-Authors: Wei-ping HuangAbstract:A wide-angle vector Beam Propagation method is developed and presented. Considerable improvement in accuracy over the paraxial vector propagating algorithms is achieved with virtually no additional computation. >
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The finite-difference vector Beam Propagation method: analysis and assessment
Journal of Lightwave Technology, 1992Co-Authors: Wei-ping Huang, Sai T. Chu, Sujeet K. ChaudhuriAbstract:The newly developed finite-difference vector Beam Propagation method (FD-VBPM) is analyzed and assessed for application to two-dimensional waveguide structures. The general formulations for the FD-VBPM are derived from the vector wave equations for the electric fields. The stability criteria, the numerical dissipation, and the dispersion of the finite-difference schemes are analyzed by applying the von Neumann method. Important issues regarding the implementation, such as the choice of reference refractive index, the application of numerical boundary conditions, and the use of numerical solution schemes, are discussed. The FD-VBPM is assessed by calculating the attenuation coefficients and the percentage errors of the Propagation constants of the TE and TM modes of a step-index slab waveguide. Several salient features of the FD-VBPM are illustrated. >
Jun Shibayama - One of the best experts on this subject based on the ideXlab platform.
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a three dimensional multistep horizontally wide angle Beam Propagation method based on the generalized douglas scheme
IEEE Photonics Technology Letters, 2006Co-Authors: Jun Shibayama, T Takahashi, J Yamauchi, H NakanoAbstract:A three-dimensional horizontally wide-angle Beam-Propagation method is formulated on the basis of the multistep method for higher order Pade approximants, together with the alternating-direction implicit scheme. The fourth-order accurate finite-difference formula is used to enhance the efficiency of the method. The effectiveness is demonstrated through the analyses of a tilted step-index waveguide and a multimode interference coupler
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a three dimensional horizontally wide angle noniterative Beam Propagation method based on the alternating direction implicit scheme
IEEE Photonics Technology Letters, 2006Co-Authors: Jun Shibayama, T Takahashi, J Yamauchi, H NakanoAbstract:A three-dimensional horizontally wide-angle Beam-Propagation method is proposed on the basis of the alternating-direction implicit scheme, in which the Pade/spl acute/ approximant is applied only to the horizontal direction. The present formulation reduces the splitting error to the first order without an iteration procedure. The effectiveness is demonstrated through the wide-angle propagating Beam analysis of a tilted optical waveguide.
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efficient time domain finite difference Beam Propagation methods for the analysis of slab and circularly symmetric waveguides
Journal of Lightwave Technology, 2000Co-Authors: Jun Shibayama, T Takahashi, J Yamauchi, H NakanoAbstract:The generalized Douglas scheme is applied to the time-domain finite difference Beam Propagation methods (TD-BPMs) in rectangular and cylindrical coordinates. High accuracy and efficiency are demonstrated through the analysis of optical pulse Propagation in slab and circularly symmetric waveguides. As an example of a reflection problem, the TD-BPM in cylindrical coordinates is applied to the analysis of a fiber Bragg grating with a sinusoidal index change. Effectiveness of the present scheme is discussed in comparison with the conventional TD-BPM and the finite-difference time-domain method.