The Experts below are selected from a list of 166149 Experts worldwide ranked by ideXlab platform
Tom G. Mackay - One of the best experts on this subject based on the ideXlab platform.
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Two Dyakonov–Voigt Surface Waves guided by a biaxial–isotropic dielectric interface
Scientific Reports, 2020Co-Authors: Chenzhang Zhou, Tom G. Mackay, Akhlesh LakhtakiaAbstract:Electromagnetic Surface Waves guided by the planar interface of an orthorhombic dielectric material and an isotropic dielectric material were analyzed theoretically and numerically. Both naturally occurring minerals (crocoite, tellurite, and cerussite) and engineered materials were considered as the orthorhombic partnering material. In addition to conventional Dyakonov Surface Waves, the analysis revealed that as many as two Dyakonov–Voigt Surface Waves can propagate in each quadrant of the interface plane, depending upon the birefringence of the orthorhombic partnering material. The coexistence of two Dyakonov–Voigt Surface Waves marks a fundamental departure from the corresponding case involving the planar interface of a uniaxial dielectric material and an isotropic dielectric material for which only one Dyakonov–Voigt Surface wave is possible. The two Dyakonov–Voigt Surface Waves propagate in different directions in each quadrant of the interface plane, with different relative phase speeds and different penetration depths. Furthermore, the localization characteristics of the two Dyakonov–Voigt Surface Waves at the planar interface are quite different: the Dyakonov–Voigt Surface wave with the higher relative phase speed is much less tightly localized at the interface in the isotropic dielectric partnering material.
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Theory of Dyakonov─Tamm Surface Waves featuring Dyakonov─Tamm─Voigt Surface Waves
Optik, 2020Co-Authors: Chenzhang Zhou, Tom G. Mackay, Akhlesh LakhtakiaAbstract:Abstract The propagation of Dyakonov–Tamm (DT) Surface Waves guided by the planar interface of two nondissipative materials A and B was investigated theoretically and numerically, via the corresponding canonical boundary-value problem. Material A is a homogeneous uniaxial dielectric material whose optic axis lies at an angle χ relative to the interface plane. Material B is an isotropic dielectric material that is periodically nonhomogeneous in the direction normal to the interface. The special case was considered in which the propagation matrix for material A is non-diagonalizable because the corresponding Surface wave — named the Dyakonov–Tamm–Voigt (DTV) Surface wave — has unusual localization characteristics. The decay of the DTV Surface wave is given by the product of a linear function and an exponential function of distance from the interface in material A ; in contrast, the fields of conventional DT Surface Waves decay only exponentially with distance from the interface. Numerical studies revealed that multiple DT Surface Waves can exist for a fixed propagation direction in the interface plane, depending upon the constitutive parameters of materials A and B . When regarded as functions of the angle of propagation in the interface plane, the multiple DT Surface-wave solutions can be organized as continuous branches. A larger number of DT solution branches exist when the degree of anisotropy of material A is greater. If χ = 0 ° , a solitary DTV solution exists for a unique propagation direction on a DT solution branch and should be regarded as the manifestation of an exceptional point. No DTV solutions exist if χ > 0 ° . As the degree of nonhomogeneity of material B decreases, the number of DT solution branches decreases. For most propagation directions in the interface plane, no solutions exist in the limiting case wherein the degree of nonhomogeneity approaches zero; but one solution persists provided that the direction of propagation falls within the angular existence domain of the corresponding Dyakonov Surface wave.
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On the Identification of Surface Waves in Numerical Studies
Plasmonics, 2019Co-Authors: Tom G. MackayAbstract:In a recent study published in this journal, in which Surface Waves were investigated numerically for a certain equichiral thin film, the criterion used to determine whether or not Surface Waves were excited is not adequately discriminating.
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electromagnetic Surface Waves a modern perspective
2013Co-Authors: John A Polo, Tom G. Mackay, Akhlesh LakhtakiaAbstract:For decades, the Surface-plasmon-polariton wave guided by the interface of simple isotropic materials dominated the scene. However, in recent times research on electromagnetic Surface Waves guided by planar interfaces has expanded into new and exciting areas. In the 1990's research focused on advancing knowledge of the newly discovered Dyakonov wave. More recently, much of the Surface wave research is motivated by the proliferation of nanotechnology and the growing number of materials available with novel properties. This book leads the reader from the relatively simple Surface-plasmon-polariton wave with isotropic materials to the latest research on various types of electromagnetic Surface Waves guided by the interfaces of complex materials enabled by recent developments in nanotechnology. This includes: Dyakonov Waves guided by interfaces formed with columnar thin films, Dyakonov-Tamm Waves guided by interfaces formed with sculptured thin films, and multiple modes of Surface-plasmon-polariton Waves guided by the interface of a metal and a periodically varying dielectric material. Gathers research from the past 5 years in a single comprehensive view of electromagnetic Surface Waves. Written by the foremost experts and researchers in the field.Layered presentation explains topics with an introductory overview level up to a highly technical level.
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Chapter 1 – Surface Waves
Electromagnetic Surface Waves, 2013Co-Authors: John A Polo, Tom G. Mackay, Akhlesh LakhtakiaAbstract:The propagation of a Surface wave is guided by the planar interface of two dissimilar materials. Although Zenneck Waves were the first to be investigated, today applications of simple Surface-plasmon-polariton Waves are commonplace. Burgeoning interest in complex materials has spurred research on other types of Surface Waves—such as Dyakonov Waves, Tamm Waves, and Dyakonov-Tamm Waves—all the more so because nanotechnologies are making it possible to engineer constitutive properties at the nanoscale. This chapter provides a bird’s-eye view of the intricacies of the Surface-wave phenomenon in relation to the constitutive properties of the partnering materials. Practical configurations as well as applications are also introduced.
Akhlesh Lakhtakia - One of the best experts on this subject based on the ideXlab platform.
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Two Dyakonov–Voigt Surface Waves guided by a biaxial–isotropic dielectric interface
Scientific Reports, 2020Co-Authors: Chenzhang Zhou, Tom G. Mackay, Akhlesh LakhtakiaAbstract:Electromagnetic Surface Waves guided by the planar interface of an orthorhombic dielectric material and an isotropic dielectric material were analyzed theoretically and numerically. Both naturally occurring minerals (crocoite, tellurite, and cerussite) and engineered materials were considered as the orthorhombic partnering material. In addition to conventional Dyakonov Surface Waves, the analysis revealed that as many as two Dyakonov–Voigt Surface Waves can propagate in each quadrant of the interface plane, depending upon the birefringence of the orthorhombic partnering material. The coexistence of two Dyakonov–Voigt Surface Waves marks a fundamental departure from the corresponding case involving the planar interface of a uniaxial dielectric material and an isotropic dielectric material for which only one Dyakonov–Voigt Surface wave is possible. The two Dyakonov–Voigt Surface Waves propagate in different directions in each quadrant of the interface plane, with different relative phase speeds and different penetration depths. Furthermore, the localization characteristics of the two Dyakonov–Voigt Surface Waves at the planar interface are quite different: the Dyakonov–Voigt Surface wave with the higher relative phase speed is much less tightly localized at the interface in the isotropic dielectric partnering material.
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Theory of Dyakonov─Tamm Surface Waves featuring Dyakonov─Tamm─Voigt Surface Waves
Optik, 2020Co-Authors: Chenzhang Zhou, Tom G. Mackay, Akhlesh LakhtakiaAbstract:Abstract The propagation of Dyakonov–Tamm (DT) Surface Waves guided by the planar interface of two nondissipative materials A and B was investigated theoretically and numerically, via the corresponding canonical boundary-value problem. Material A is a homogeneous uniaxial dielectric material whose optic axis lies at an angle χ relative to the interface plane. Material B is an isotropic dielectric material that is periodically nonhomogeneous in the direction normal to the interface. The special case was considered in which the propagation matrix for material A is non-diagonalizable because the corresponding Surface wave — named the Dyakonov–Tamm–Voigt (DTV) Surface wave — has unusual localization characteristics. The decay of the DTV Surface wave is given by the product of a linear function and an exponential function of distance from the interface in material A ; in contrast, the fields of conventional DT Surface Waves decay only exponentially with distance from the interface. Numerical studies revealed that multiple DT Surface Waves can exist for a fixed propagation direction in the interface plane, depending upon the constitutive parameters of materials A and B . When regarded as functions of the angle of propagation in the interface plane, the multiple DT Surface-wave solutions can be organized as continuous branches. A larger number of DT solution branches exist when the degree of anisotropy of material A is greater. If χ = 0 ° , a solitary DTV solution exists for a unique propagation direction on a DT solution branch and should be regarded as the manifestation of an exceptional point. No DTV solutions exist if χ > 0 ° . As the degree of nonhomogeneity of material B decreases, the number of DT solution branches decreases. For most propagation directions in the interface plane, no solutions exist in the limiting case wherein the degree of nonhomogeneity approaches zero; but one solution persists provided that the direction of propagation falls within the angular existence domain of the corresponding Dyakonov Surface wave.
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electromagnetic Surface Waves a modern perspective
2013Co-Authors: John A Polo, Tom G. Mackay, Akhlesh LakhtakiaAbstract:For decades, the Surface-plasmon-polariton wave guided by the interface of simple isotropic materials dominated the scene. However, in recent times research on electromagnetic Surface Waves guided by planar interfaces has expanded into new and exciting areas. In the 1990's research focused on advancing knowledge of the newly discovered Dyakonov wave. More recently, much of the Surface wave research is motivated by the proliferation of nanotechnology and the growing number of materials available with novel properties. This book leads the reader from the relatively simple Surface-plasmon-polariton wave with isotropic materials to the latest research on various types of electromagnetic Surface Waves guided by the interfaces of complex materials enabled by recent developments in nanotechnology. This includes: Dyakonov Waves guided by interfaces formed with columnar thin films, Dyakonov-Tamm Waves guided by interfaces formed with sculptured thin films, and multiple modes of Surface-plasmon-polariton Waves guided by the interface of a metal and a periodically varying dielectric material. Gathers research from the past 5 years in a single comprehensive view of electromagnetic Surface Waves. Written by the foremost experts and researchers in the field.Layered presentation explains topics with an introductory overview level up to a highly technical level.
-
Chapter 1 – Surface Waves
Electromagnetic Surface Waves, 2013Co-Authors: John A Polo, Tom G. Mackay, Akhlesh LakhtakiaAbstract:The propagation of a Surface wave is guided by the planar interface of two dissimilar materials. Although Zenneck Waves were the first to be investigated, today applications of simple Surface-plasmon-polariton Waves are commonplace. Burgeoning interest in complex materials has spurred research on other types of Surface Waves—such as Dyakonov Waves, Tamm Waves, and Dyakonov-Tamm Waves—all the more so because nanotechnologies are making it possible to engineer constitutive properties at the nanoscale. This chapter provides a bird’s-eye view of the intricacies of the Surface-wave phenomenon in relation to the constitutive properties of the partnering materials. Practical configurations as well as applications are also introduced.
Zhenghua Qia - One of the best experts on this subject based on the ideXlab platform.
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transverse Surface Waves in functionally graded piezoelectric materials with exponential variation
Smart Materials and Structures, 2008Co-Authors: Zhenghua Qia, Kikuo KishimotoAbstract:For a functionally graded piezoelectric substrate with exponential variation, the existence and propagation behavior of transverse Surface Waves is studied by analytical technique. The dispersion equations for the existence of the transverse Surface Waves with respect to phase velocity are obtained for both electrically open and short conditions. A detailed investigation of the effect of gradient coefficient on dispersion relation, phase velocity, group velocity and electromechanical coupling factor is carried out. It is found by numerical examples that adjusting gradient coefficient makes the electromechanical coupling factor of the transverse Surface Waves achieve quite high values at some appropriate wavenumber, and at the same time, the penetration depth can be reduced to the same order as the wavelength under electrically short case. Because of the negligible initial stress in functionally graded piezoelectric materials, this model could serve as an excellent substitute for the typical layered piezoelectric structures used in Surface acoustic wave (SAW) devices, thus providing a theoretical foundation for designing SAW devices with high performance.
Chenzhang Zhou - One of the best experts on this subject based on the ideXlab platform.
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Two Dyakonov–Voigt Surface Waves guided by a biaxial–isotropic dielectric interface
Scientific Reports, 2020Co-Authors: Chenzhang Zhou, Tom G. Mackay, Akhlesh LakhtakiaAbstract:Electromagnetic Surface Waves guided by the planar interface of an orthorhombic dielectric material and an isotropic dielectric material were analyzed theoretically and numerically. Both naturally occurring minerals (crocoite, tellurite, and cerussite) and engineered materials were considered as the orthorhombic partnering material. In addition to conventional Dyakonov Surface Waves, the analysis revealed that as many as two Dyakonov–Voigt Surface Waves can propagate in each quadrant of the interface plane, depending upon the birefringence of the orthorhombic partnering material. The coexistence of two Dyakonov–Voigt Surface Waves marks a fundamental departure from the corresponding case involving the planar interface of a uniaxial dielectric material and an isotropic dielectric material for which only one Dyakonov–Voigt Surface wave is possible. The two Dyakonov–Voigt Surface Waves propagate in different directions in each quadrant of the interface plane, with different relative phase speeds and different penetration depths. Furthermore, the localization characteristics of the two Dyakonov–Voigt Surface Waves at the planar interface are quite different: the Dyakonov–Voigt Surface wave with the higher relative phase speed is much less tightly localized at the interface in the isotropic dielectric partnering material.
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Theory of Dyakonov─Tamm Surface Waves featuring Dyakonov─Tamm─Voigt Surface Waves
Optik, 2020Co-Authors: Chenzhang Zhou, Tom G. Mackay, Akhlesh LakhtakiaAbstract:Abstract The propagation of Dyakonov–Tamm (DT) Surface Waves guided by the planar interface of two nondissipative materials A and B was investigated theoretically and numerically, via the corresponding canonical boundary-value problem. Material A is a homogeneous uniaxial dielectric material whose optic axis lies at an angle χ relative to the interface plane. Material B is an isotropic dielectric material that is periodically nonhomogeneous in the direction normal to the interface. The special case was considered in which the propagation matrix for material A is non-diagonalizable because the corresponding Surface wave — named the Dyakonov–Tamm–Voigt (DTV) Surface wave — has unusual localization characteristics. The decay of the DTV Surface wave is given by the product of a linear function and an exponential function of distance from the interface in material A ; in contrast, the fields of conventional DT Surface Waves decay only exponentially with distance from the interface. Numerical studies revealed that multiple DT Surface Waves can exist for a fixed propagation direction in the interface plane, depending upon the constitutive parameters of materials A and B . When regarded as functions of the angle of propagation in the interface plane, the multiple DT Surface-wave solutions can be organized as continuous branches. A larger number of DT solution branches exist when the degree of anisotropy of material A is greater. If χ = 0 ° , a solitary DTV solution exists for a unique propagation direction on a DT solution branch and should be regarded as the manifestation of an exceptional point. No DTV solutions exist if χ > 0 ° . As the degree of nonhomogeneity of material B decreases, the number of DT solution branches decreases. For most propagation directions in the interface plane, no solutions exist in the limiting case wherein the degree of nonhomogeneity approaches zero; but one solution persists provided that the direction of propagation falls within the angular existence domain of the corresponding Dyakonov Surface wave.
Kikuo Kishimoto - One of the best experts on this subject based on the ideXlab platform.
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transverse Surface Waves in functionally graded piezoelectric materials with exponential variation
Smart Materials and Structures, 2008Co-Authors: Zhenghua Qia, Kikuo KishimotoAbstract:For a functionally graded piezoelectric substrate with exponential variation, the existence and propagation behavior of transverse Surface Waves is studied by analytical technique. The dispersion equations for the existence of the transverse Surface Waves with respect to phase velocity are obtained for both electrically open and short conditions. A detailed investigation of the effect of gradient coefficient on dispersion relation, phase velocity, group velocity and electromechanical coupling factor is carried out. It is found by numerical examples that adjusting gradient coefficient makes the electromechanical coupling factor of the transverse Surface Waves achieve quite high values at some appropriate wavenumber, and at the same time, the penetration depth can be reduced to the same order as the wavelength under electrically short case. Because of the negligible initial stress in functionally graded piezoelectric materials, this model could serve as an excellent substitute for the typical layered piezoelectric structures used in Surface acoustic wave (SAW) devices, thus providing a theoretical foundation for designing SAW devices with high performance.
