The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Susumu Noda - One of the best experts on this subject based on the ideXlab platform.
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three dimensional coupled Wave Model for square lattice photonic crystal lasers with transverse electric polarization a general approach
Physical Review B, 2011Co-Authors: Yong Liang, Kyosuke Sakai, Chao Peng, Seita Iwahashi, Susumu NodaAbstract:A general coupled-Wave Model is presented for square-lattice photonic crystal (PC) lasers with transverse-electric polarization. This Model presents a realistic treatment of the full three-dimensional structure of typical laser devices by incorporating the surface emission and high-order coupling effects. Numerical examples based on our Model are presented for various PC structures with different air-hole shapes. The accuracy of the results is verified using three-dimensional finite-difference time-domain simulations. Using this Model, we demonstrate that the PC lattice with asymmetric air holes can give rise to a high-output power, efficient device.
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three dimensional coupled Wave Model for square lattice photonic crystal lasers with transverse electric polarization a general approach
Physical Review B, 2011Co-Authors: Yong Liang, Kyosuke Sakai, Chao Peng, Seita Iwahashi, Susumu NodaAbstract:A general coupled-Wave Model is presented for square-lattice photonic crystal (PC) lasers with transverse-electric polarization. This Model incorporates the high-order coupling effects that are important for two-dimensional PC laser cavities and gives a general and rigorous coupled-Wave formulation for the full three-dimensional structures of typical laser devices. Numerical examples based on our Model are presented for PC structures with different air-hole shapes. The accuracy of the results obtained is verified using three-dimensional finite-difference time-domain simulations.
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coupled Wave Model for square lattice two dimensional photonic crystal with transverse electric like mode
Applied Physics Letters, 2006Co-Authors: Kyosuke Sakai, Eiji Miyai, Susumu NodaAbstract:We propose a coupled-Wave Model for a square-lattice two-dimensional (2D) photonic crystal (PC) with a transverse electric mode. A set of coupled-Wave equations is obtained from this Model and it is shown that 2D optical coupling occurs between four light Waves propagating in the Γ-X direction via higher-order Waves propagating in the Γ-M direction. The expressions for the resonant mode frequencies derived from the coupled-Wave equations describe the characteristics of experimental results for the band-edge frequencies of the 2D PC laser.
Changsheng Chen - One of the best experts on this subject based on the ideXlab platform.
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an unstructured grid finite volume surface Wave Model fvcom sWave implementation validations and applications
Ocean Modelling, 2009Co-Authors: Changsheng Chen, Robert C Beardsley, William Perrie, Geoffrey W Cowles, Zhigang LaiAbstract:Abstract The structured-grid surface Wave Model SWAN (Simulating Waves Nearshore) has been converted into an unstructured-grid finite-volume version (hereafter referred to as FVCOM-SWave) for use in coastal ocean regions with complex irregular geometry. The implementation is made using the Flux-Corrected Transport (FCT) algorithm in frequency space, the implicit Crank–Nicolson method in directional space and options of explicit or implicit second-order upwind finite-volume schemes in geographic space. FVCOM-SWave is validated using four idealized benchmark test problems with emphasis on numerical dispersion, Wave-current interactions, Wave propagation over a varying-bathymetry shallow water region, and the basic Wave grow curves. Results demonstrate that in the rectangular geometric domain, the second-order finite-volume method used in FVCOM-SWave has the same accuracy as the third-order finite-difference method used in SWAN. FVCOM-SWave was then applied to simulate wind-induced surface Waves on the US northeast shelf with a central focus in the Gulf of Maine and New England Shelf. Through improved geometric fitting of the complex irregular coastline, FVCOM-SWave was able to robustly capture the spatial and temporal variation of surface Waves in both deep and shallow regions along the US northeast coast.
Kyosuke Sakai - One of the best experts on this subject based on the ideXlab platform.
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three dimensional coupled Wave Model for square lattice photonic crystal lasers with transverse electric polarization a general approach
Physical Review B, 2011Co-Authors: Yong Liang, Kyosuke Sakai, Chao Peng, Seita Iwahashi, Susumu NodaAbstract:A general coupled-Wave Model is presented for square-lattice photonic crystal (PC) lasers with transverse-electric polarization. This Model presents a realistic treatment of the full three-dimensional structure of typical laser devices by incorporating the surface emission and high-order coupling effects. Numerical examples based on our Model are presented for various PC structures with different air-hole shapes. The accuracy of the results is verified using three-dimensional finite-difference time-domain simulations. Using this Model, we demonstrate that the PC lattice with asymmetric air holes can give rise to a high-output power, efficient device.
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three dimensional coupled Wave Model for square lattice photonic crystal lasers with transverse electric polarization a general approach
Physical Review B, 2011Co-Authors: Yong Liang, Kyosuke Sakai, Chao Peng, Seita Iwahashi, Susumu NodaAbstract:A general coupled-Wave Model is presented for square-lattice photonic crystal (PC) lasers with transverse-electric polarization. This Model incorporates the high-order coupling effects that are important for two-dimensional PC laser cavities and gives a general and rigorous coupled-Wave formulation for the full three-dimensional structures of typical laser devices. Numerical examples based on our Model are presented for PC structures with different air-hole shapes. The accuracy of the results obtained is verified using three-dimensional finite-difference time-domain simulations.
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coupled Wave Model for square lattice two dimensional photonic crystal with transverse electric like mode
Applied Physics Letters, 2006Co-Authors: Kyosuke Sakai, Eiji Miyai, Susumu NodaAbstract:We propose a coupled-Wave Model for a square-lattice two-dimensional (2D) photonic crystal (PC) with a transverse electric mode. A set of coupled-Wave equations is obtained from this Model and it is shown that 2D optical coupling occurs between four light Waves propagating in the Γ-X direction via higher-order Waves propagating in the Γ-M direction. The expressions for the resonant mode frequencies derived from the coupled-Wave equations describe the characteristics of experimental results for the band-edge frequencies of the 2D PC laser.
L H Holthuijsen - One of the best experts on this subject based on the ideXlab platform.
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diffusion reduction in an arbitrary scale third generation wind Wave Model
Ocean Engineering, 2002Co-Authors: W E Rogers, James M Kaihatu, H A H Petit, Nico Booij, L H HolthuijsenAbstract:Abstract The numerical schemes for the geographic propagation of random, short-crested, wind-generated Waves in third-generation Wave Models are either unconditionally stable or only conditionally stable. Having an unconditionally stable scheme gives greater freedom in choosing the time step (for given space steps). The third-generation Wave Model SWAN (“Simulated Waves Nearshore”, Booij et al., 1999 ) has been implemented with this type of scheme. This Model uses a first order, upwind, implicit numerical scheme for geographic propagation. The scheme can be employed for both stationary (typically small scale) and nonstationary (i.e. time-stepping) computations. Though robust, this first order scheme is very diffusive. This degrades the accuracy of the Model in a number of situations, including most Model applications at larger scales. The authors reduce the diffusiveness of the Model by replacing the existing numerical scheme with two alternative higher order schemes, a scheme that is intended for stationary, small-scale computations, and a scheme that is most appropriate for nonstationary computations. Examples representative of both large-scale and small-scale applications are presented. The alternative schemes are shown to be much less diffusive than the original scheme while retaining the implicit character of the particular SWAN set-up. The additional computational burden of the stationary alternative scheme is negligible, and the expense of the nonstationary alternative scheme is comparable to those used by other third generation Wave Models. To further accommodate large-scale applications of SWAN, the Model is reformulated in terms of spherical coordinates rather than the original Cartesian coordinates. Thus the modified Model can calculate Wave energy propagation accurately and efficiently at any scale varying from laboratory dimensions (spatial scale O(10 m) with resolution O(0.1 m)), to near-shore coastal dimension (spatial scale O(10 km) with resolution O(100 m)) to oceanic dimensions (spatial scale O(10 000 km) with resolution O(100 km).
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a third generation Wave Model for coastal regions 2 verification
Journal of Geophysical Research, 1999Co-Authors: R C Ris, L H Holthuijsen, N BooijAbstract:A third-generation spectral Wave Model (Simulating Waves Nearshore (SWAN)) for small-scale, coastal regions with shallow water, (barrier) islands, tidal flats, local wind, and ambient currents is verified in stationary mode with measurements in five real field cases. These verification cases represent an increasing complexity in two- dimensional bathymetry and added presence of currents. In the most complex of these cases, the Waves propagate through a tidal gap between two barrier islands into a bathymetry of channels and shoals with tidal currents where the Waves are regenerated by a local wind. The Wave fields were highly variable with up to 3 orders of magnitude difference in energy scale in individual cases. The Model accounts for shoaling, refraction, generation by wind, whitecapping, triad and quadruplet Wave-Wave interactions, and bottom and depth-induced Wave breaking. The effect of alternative formulations of these processes is shown. In all cases a relatively large number of Wave observations is available, including observations of Wave directions. The average rms error in the computed significant Wave height and mean Wave period is 0.30 m and 0.7 s, respectively, which is 10% of the incident values for both.
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a third generation Wave Model for coastal regions 1 Model description and validation
Journal of Geophysical Research, 1999Co-Authors: N Booij, R C Ris, L H HolthuijsenAbstract:A third-generation numerical Wave Model to compute random, short-crested Waves in coastal regions with shallow water and ambient currents (Simulating Waves Nearshore (SWAN)) has been developed, implemented, and validated. The Model is based on a Eulerian formulation of the discrete spectral balance of action density that accounts for refractive propagation over arbitrary bathymetry and current fields. It is driven by boundary conditions and local winds. As in other third-generation Wave Models, the processes of wind generation, whitecapping, quadruplet Wave-Wave interactions, and bottom dissipation are represented explicitly. In SWAN, triad Wave-Wave interactions and depth-induced Wave breaking are added. In contrast to other third-generation Wave Models, the numerical propagation scheme is implicit, which implies that the computations are more economic in shallow water. The Model results agree well with analytical solutions, laboratory observations, and (generalized) field observations.
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the swan Wave Model for shallow water
25th International Conference on Coastal Engineering, 1997Co-Authors: N Booij, L H Holthuijsen, R C RisAbstract:The numerical Model SWAN (Simulating Waves Nearshore) for the computation of Wave conditions in shallow water with ambient currents is briefly described. The Model is based on a fully spectral representation of the action balance equation with all physical processes Modelled explicitly. No a priori limitations are imposed on the spectral evolution. This makes the Model a third-generation Model. In Holthuijsen et al. (1993) and Ris et al. (1994) test cases for propagation, generation and dissipation have been shown without currents. Current effects have now been added and academic cases are shown here. The Model is also applied in a fairly academic case of a shallow lake (Lake George, Australia) and in a complex, realistic case of an inter-tidal area with currents (Friesche Zeegat, the Netherlands). The results are compared with observations. A new development to formulate the Model on a curvi-linear grid to accommodate linkage to hydro-dynamic circulation Models is presented and a first test is shown.
N Booij - One of the best experts on this subject based on the ideXlab platform.
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a third generation Wave Model for coastal regions 2 verification
Journal of Geophysical Research, 1999Co-Authors: R C Ris, L H Holthuijsen, N BooijAbstract:A third-generation spectral Wave Model (Simulating Waves Nearshore (SWAN)) for small-scale, coastal regions with shallow water, (barrier) islands, tidal flats, local wind, and ambient currents is verified in stationary mode with measurements in five real field cases. These verification cases represent an increasing complexity in two- dimensional bathymetry and added presence of currents. In the most complex of these cases, the Waves propagate through a tidal gap between two barrier islands into a bathymetry of channels and shoals with tidal currents where the Waves are regenerated by a local wind. The Wave fields were highly variable with up to 3 orders of magnitude difference in energy scale in individual cases. The Model accounts for shoaling, refraction, generation by wind, whitecapping, triad and quadruplet Wave-Wave interactions, and bottom and depth-induced Wave breaking. The effect of alternative formulations of these processes is shown. In all cases a relatively large number of Wave observations is available, including observations of Wave directions. The average rms error in the computed significant Wave height and mean Wave period is 0.30 m and 0.7 s, respectively, which is 10% of the incident values for both.
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a third generation Wave Model for coastal regions 1 Model description and validation
Journal of Geophysical Research, 1999Co-Authors: N Booij, R C Ris, L H HolthuijsenAbstract:A third-generation numerical Wave Model to compute random, short-crested Waves in coastal regions with shallow water and ambient currents (Simulating Waves Nearshore (SWAN)) has been developed, implemented, and validated. The Model is based on a Eulerian formulation of the discrete spectral balance of action density that accounts for refractive propagation over arbitrary bathymetry and current fields. It is driven by boundary conditions and local winds. As in other third-generation Wave Models, the processes of wind generation, whitecapping, quadruplet Wave-Wave interactions, and bottom dissipation are represented explicitly. In SWAN, triad Wave-Wave interactions and depth-induced Wave breaking are added. In contrast to other third-generation Wave Models, the numerical propagation scheme is implicit, which implies that the computations are more economic in shallow water. The Model results agree well with analytical solutions, laboratory observations, and (generalized) field observations.
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the swan Wave Model for shallow water
25th International Conference on Coastal Engineering, 1997Co-Authors: N Booij, L H Holthuijsen, R C RisAbstract:The numerical Model SWAN (Simulating Waves Nearshore) for the computation of Wave conditions in shallow water with ambient currents is briefly described. The Model is based on a fully spectral representation of the action balance equation with all physical processes Modelled explicitly. No a priori limitations are imposed on the spectral evolution. This makes the Model a third-generation Model. In Holthuijsen et al. (1993) and Ris et al. (1994) test cases for propagation, generation and dissipation have been shown without currents. Current effects have now been added and academic cases are shown here. The Model is also applied in a fairly academic case of a shallow lake (Lake George, Australia) and in a complex, realistic case of an inter-tidal area with currents (Friesche Zeegat, the Netherlands). The results are compared with observations. A new development to formulate the Model on a curvi-linear grid to accommodate linkage to hydro-dynamic circulation Models is presented and a first test is shown.
