Oleksandr Zhuromskyy | Friedrich-Alexander-Universität Erlangen-Nürnberg (original) (raw)
Papers by Oleksandr Zhuromskyy
Journal of Lightwave Technology, 2000
ABSTRACT We describe a 4-channel metro ring node module that performs add/drop, protection switch... more ABSTRACT We describe a 4-channel metro ring node module that performs add/drop, protection switching, and power equalization functionalities on a single chip. The worst-case insertion loss is 1.25 dB.
Optics Communications, 1998
Phase matching between the fundamental TE and TM modes is an essential condition for complete pol... more Phase matching between the fundamental TE and TM modes is an essential condition for complete polarization rotation in magnetooptic waveguides with longitudinally directed magnetization. This condition can be satisfied with embedded square waveguides or with raised strip waveguides, provided that the core dimensions are suitably chosen. Based on coupled mode theory for the vectorial modes of rectangular isotropic waveguides, we numerically simulate the performance of such devices in an experimental isolator setup, including birefringence and optical absorption. Fabrication tolerances with respect to all relevant parameters can be evaluated by simple perturbational expressions. Numerical verification shows that these formulas are accurate enough for practical purposes. The tolerances qualify the traditional polarization rotator setup as competitive to recent proposals for integrated optical isolators based on nonreciprocal interferometry.
2013 7th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics, 2013
ABSTRACT Loss less propagation of longitudinal magnetic-dipole waves is predicted for regular cha... more ABSTRACT Loss less propagation of longitudinal magnetic-dipole waves is predicted for regular chains of rutile particles. Rigorous T-matrix simulation techniques are applied to deduce the dispersion characteristics of the dipole waves and to optimize the properties of the closing elements in the waveguide for maximum power transmission. The proposed technique can be used to optimize the interaction between light and particle ensembles.
Magnetooptical waveguides having nonreciprocal phase shift for both TE and TM modes can be prepar... more Magnetooptical waveguides having nonreciprocal phase shift for both TE and TM modes can be prepared by properly adjusting the spatial variation of the Faraday rotation. Such waveguides are attractive to realize optical isolators. We investigate four concepts of magnetooptical waveguides which yield equal nonreciprocal phase shifts for the fundamental TE and TM modes. A polarization-independent Mach-Zehnder-type integrated optical isolator is
Metamaterials VIII, 2013
ABSTRACT Circuit model analysis extensively used to describe metamaterials response at radio and ... more ABSTRACT Circuit model analysis extensively used to describe metamaterials response at radio and microwave frequencies needs significant revision for application to metallic resonators in the infrared frequency range. A self consistent filament current based approach is elaborated providing parameter values accurately describing resonators internal properties as well as inter-resonator couplings. The model is verified by comparing the excitations in a five element array obtained from the numerical simulation using CST MWS solver with the predictions provided by the model. Although the results presented here concern with loop like magnetic resonators, the model can also be extended to other resonator shapes, for example metallic rods.
Photonic Integrated Systems, 2003
We report on a hybrid integrated metro ring node subsystem on a chip that consists of an array of... more We report on a hybrid integrated metro ring node subsystem on a chip that consists of an array of four independent reconfigurable optical add-drop circuits, each with power monitoring and automatic load balancing, and supporting shared and dedicated protection protocols in two-fiber metro ring optical networks.
Physical Review B
Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwaveleng... more Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwavelength particles is predicted for a narrow frequency range around the magnetic Mie resonance of the individual particles. Mathematical analogies between dipole and magnetoinductive waves are used to reduce back-reflections thus improving the power transfer efficiency of respective particle waveguides. The proposed technique can be used to optimize the propagation of even more complex particle-based configurations.
Small particles are exploited for their optical properties in a vast array of applications such a... more Small particles are exploited for their optical properties in a vast array of applications such as paint, inks, textiles and cosmetics. In many of these application areas, features of the particles (size, shape and topology) can be on the nanoscale, a fact which is often fundamentally important to their desirable properties. With the broad range of relevant product areas, future development of new optical materials will require an intimate understanding of this microstructure-function relationship in order to improve cost efficiency, environmental safety and sustainability. At the same time, there needs to be a shift from materials development through empirical synthetic experiments towards a “process chain” linking theoretical design to the practical realization of application-optimized particles. Making this possible are significant advances, on the one hand in computational tools which allow the inversion of optical simulation for the discovery of non-intuitive structures, and on...
Metamaterials, 2005
The dispersion equation of a magneto-inductive wave along a line of magnetically coupled resonant... more The dispersion equation of a magneto-inductive wave along a line of magnetically coupled resonant elements is investigated under conditions when retardation must be taken into account. It is shown that both the radiation resistance and the imaginary part of the mutual inductance appear in the modified dispersion equation which allows interaction up to the pth neighbour. The problems arising in the solution of the full dispersion equation are discussed and it is concluded that the general solution leading to a large number of high-attenuation branches may not lead to a solution that is easily interpretable physically. It is suggested that the dispersion equation is to be derived from the variation of the current along an array of a finite number of elements excited by a voltage applied to the first element. The solution is obtained for a planar array of capacitively loaded loops in a closed form by inverting the complex mutual inductance matrix. It is shown that retardation and higher order interactions have greater effect upon the attenuation of the arising backward wave than upon the phase change per element. The appearance of a forward wave with a phase velocity close to that of light is also shown.
Plasmonics: Metallic Nanostructures and Their Optical Properties IX, 2011
ABSTRACT Properties of split-ring metamaterials are governed by inter-element interactions. These... more ABSTRACT Properties of split-ring metamaterials are governed by inter-element interactions. These interactions lead to slow eigenmodes of coupling, which, due to their short wavelengths, are ideal candidates for the design of near-field manipulating devices. In this paper we explore the electric and magnetic coupling mechanisms in nano-U and nano-SRR dimers comprising of two identical nano-resonators arranged axially and twisted relative to each other by an arbitrary angle. We study theoretically the couplings in a periodic chain of nano-dimers for the frequencies from 100 to 300 THz. In our analytical model, the electric and magnetic couplings can be expressed through the self and mutual terms for the magnetic and electric field energy. In addition, we incorporate the effect of kinetic inductance due to the inertia of the electrons (noticeable as element dimensions approach 100nm or smaller). The resulting dependence of the electric, magnetic and the total coupling constants on the twist angle within the dimer obtained analytically is shown to agree with numerical simulations (CST Microwave Studio). Our approach should enable an effective design of metamaterial structures with desired properties and would be a useful tool in developing THz range manipulating devices based on propagation of slow waves by virtue of coupling.
Metamaterials, 2005
ABSTRACT We describe subwavelength properties of magnetic metamaterials designed to manipulate an... more ABSTRACT We describe subwavelength properties of magnetic metamaterials designed to manipulate and control the near field by employing magnetoinductive (MI) waves. MI waves owe their existence to the magnetic coupling between metamaterial elements. Magnetic field distributions and Poynting vector streamlines are used to visualise the diamagnetic and paramagnetic properties of metamaterials and to analyse working principles of MI waveguides and MI waveguide components.
Integrated Photonics Research, 2003
ABSTRACT The integration of magneto-optical devices enables cost and size reduction in optical co... more ABSTRACT The integration of magneto-optical devices enables cost and size reduction in optical commutication systems. Nonreciprocal phase shifters can be used to build polarization independent isolators and circulators. New photonic bandgap materials with high Faraday rotation make conventional magneto-optic device concepts suitable for PLC integration
Optics express, Jan 14, 2005
The current and field distribution in a 2D metamaterial consisting of resonant elements in a hexa... more The current and field distribution in a 2D metamaterial consisting of resonant elements in a hexagonal arrangement are found assuming magnetic interaction between the elements. The dispersion equation of magnetoinductive (MI) waves is derived with the aid of the direct and reciprocal lattice familiar from solid state theory. A continuous model for the current variation in the elements is introduced leading to the familiar wave equation in the form of a second order differential equation. The current distributions are shown to exhibit a series of spatial resonances for rectangular, circular and hexagonal boundaries. The axial and radial components of the resulting magnetic field are compared with previously obtained experimental results on a Swiss Roll metamaterial with hexagonal boundaries. Experimental and theoretical results are also compared for the near field image of an object in the shape of the letter M followed by a more general discussion of imaging. It is concluded that a ...
Accurate calculation of guided modes is one of the principal tasks of numerically simulating inte... more Accurate calculation of guided modes is one of the principal tasks of numerically simulating integrated optical devices. Our recently proposed 'wave-matching-method' for dielectric waveguides with rectangular and piecewise constant refractive index profiles is based on expansions of the electromagnetic field into functions with harmonic and exponential dependence on the transverse coordinates. Local expansions for regions with constant permittivity are joined by minimizing a least squares expression for the remaining misfit at the discontinuity lines. We apply the wave-matching analysis to a number of more complex structures: a conventional, deeply etched two-waveguide coupler, an ARROW-waveguide, a three dimensional four-waveguide coupler and a three-waveguide coupler with multimode central rib.
Coupled mode theory is applied to an arrangement of three raised strip waveguides with a multimod... more Coupled mode theory is applied to an arrangement of three raised strip waveguides with a multimode central strip. We use semivectorial numerically computed modes of the three single isolated waveguides as a basis for a propagating supermode analysis of the entire structure. The pronounced polarization dependence of the raised strip guides allows for the design of a conveniently short polarization splitter. We discuss design guidelines and estimate the fabrication tolerances. The accuracy of the coupled mode approach is assessed by comparison with rigorously computed supermodes for comparable two waveguide couplers. Both types of structures indicate the limits in the applicability of the coupled mode model.
Photonic Crystal Materials and Devices X, 2012
ABSTRACT The transformation of 2-dimensional slab photonic crystal into 2-dimensional photonic gl... more ABSTRACT The transformation of 2-dimensional slab photonic crystal into 2-dimensional photonic glass was achieved by gradually increasing the sphere spacing and by randomising the lattice. The materials were prepared by assembling colloidal particles at the air/water interface using a Langmuir-Blodgett trough and the subsequent deposition on glass substrates. Highly ordered monolayers were obtained by using colloids of one size, while use particles of two different sizes and different partial concentrations allows to increase the spacing of the larger spheres and to randomize the lattice. Changes in the spheres arrangements result in a change of in-plane light propagation from band-like to hopping photon transport.
ABSTRACT Metamaterials acquire their functionality from the structuring of small building blocks,... more ABSTRACT Metamaterials acquire their functionality from the structuring of small building blocks, "artificial atoms". Understanding the nature of the resonance behavior of unit cells is crucial for designing a structure with desired properties. In this paper we study the resonant behavior of metallic nanoparticles in the region of hundreds of THz, including square-cross-section nanorods, split squares, and split rings. For a better understanding of the resonant behavior of plasmonic nanoparticles we investigated standing wave patterns of surface plasmon polaritons on nanoparticles of different shapes. Our numerical results (CST Microwave Studio) suggest that the resonant behavior of each of these particles is similar to that of periodic arrays of nanorods with specific lengths and periodicities. For the first time to our knowledge, the interaction of the gap edges of a split ring, previously described in terms of the self-capacitance, has been interpreted in terms of coupled plasmonic modes.
Journal of Lightwave Technology, 2000
ABSTRACT We describe a 4-channel metro ring node module that performs add/drop, protection switch... more ABSTRACT We describe a 4-channel metro ring node module that performs add/drop, protection switching, and power equalization functionalities on a single chip. The worst-case insertion loss is 1.25 dB.
Optics Communications, 1998
Phase matching between the fundamental TE and TM modes is an essential condition for complete pol... more Phase matching between the fundamental TE and TM modes is an essential condition for complete polarization rotation in magnetooptic waveguides with longitudinally directed magnetization. This condition can be satisfied with embedded square waveguides or with raised strip waveguides, provided that the core dimensions are suitably chosen. Based on coupled mode theory for the vectorial modes of rectangular isotropic waveguides, we numerically simulate the performance of such devices in an experimental isolator setup, including birefringence and optical absorption. Fabrication tolerances with respect to all relevant parameters can be evaluated by simple perturbational expressions. Numerical verification shows that these formulas are accurate enough for practical purposes. The tolerances qualify the traditional polarization rotator setup as competitive to recent proposals for integrated optical isolators based on nonreciprocal interferometry.
2013 7th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics, 2013
ABSTRACT Loss less propagation of longitudinal magnetic-dipole waves is predicted for regular cha... more ABSTRACT Loss less propagation of longitudinal magnetic-dipole waves is predicted for regular chains of rutile particles. Rigorous T-matrix simulation techniques are applied to deduce the dispersion characteristics of the dipole waves and to optimize the properties of the closing elements in the waveguide for maximum power transmission. The proposed technique can be used to optimize the interaction between light and particle ensembles.
Magnetooptical waveguides having nonreciprocal phase shift for both TE and TM modes can be prepar... more Magnetooptical waveguides having nonreciprocal phase shift for both TE and TM modes can be prepared by properly adjusting the spatial variation of the Faraday rotation. Such waveguides are attractive to realize optical isolators. We investigate four concepts of magnetooptical waveguides which yield equal nonreciprocal phase shifts for the fundamental TE and TM modes. A polarization-independent Mach-Zehnder-type integrated optical isolator is
Metamaterials VIII, 2013
ABSTRACT Circuit model analysis extensively used to describe metamaterials response at radio and ... more ABSTRACT Circuit model analysis extensively used to describe metamaterials response at radio and microwave frequencies needs significant revision for application to metallic resonators in the infrared frequency range. A self consistent filament current based approach is elaborated providing parameter values accurately describing resonators internal properties as well as inter-resonator couplings. The model is verified by comparing the excitations in a five element array obtained from the numerical simulation using CST MWS solver with the predictions provided by the model. Although the results presented here concern with loop like magnetic resonators, the model can also be extended to other resonator shapes, for example metallic rods.
Photonic Integrated Systems, 2003
We report on a hybrid integrated metro ring node subsystem on a chip that consists of an array of... more We report on a hybrid integrated metro ring node subsystem on a chip that consists of an array of four independent reconfigurable optical add-drop circuits, each with power monitoring and automatic load balancing, and supporting shared and dedicated protection protocols in two-fiber metro ring optical networks.
Physical Review B
Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwaveleng... more Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwavelength particles is predicted for a narrow frequency range around the magnetic Mie resonance of the individual particles. Mathematical analogies between dipole and magnetoinductive waves are used to reduce back-reflections thus improving the power transfer efficiency of respective particle waveguides. The proposed technique can be used to optimize the propagation of even more complex particle-based configurations.
Small particles are exploited for their optical properties in a vast array of applications such a... more Small particles are exploited for their optical properties in a vast array of applications such as paint, inks, textiles and cosmetics. In many of these application areas, features of the particles (size, shape and topology) can be on the nanoscale, a fact which is often fundamentally important to their desirable properties. With the broad range of relevant product areas, future development of new optical materials will require an intimate understanding of this microstructure-function relationship in order to improve cost efficiency, environmental safety and sustainability. At the same time, there needs to be a shift from materials development through empirical synthetic experiments towards a “process chain” linking theoretical design to the practical realization of application-optimized particles. Making this possible are significant advances, on the one hand in computational tools which allow the inversion of optical simulation for the discovery of non-intuitive structures, and on...
Metamaterials, 2005
The dispersion equation of a magneto-inductive wave along a line of magnetically coupled resonant... more The dispersion equation of a magneto-inductive wave along a line of magnetically coupled resonant elements is investigated under conditions when retardation must be taken into account. It is shown that both the radiation resistance and the imaginary part of the mutual inductance appear in the modified dispersion equation which allows interaction up to the pth neighbour. The problems arising in the solution of the full dispersion equation are discussed and it is concluded that the general solution leading to a large number of high-attenuation branches may not lead to a solution that is easily interpretable physically. It is suggested that the dispersion equation is to be derived from the variation of the current along an array of a finite number of elements excited by a voltage applied to the first element. The solution is obtained for a planar array of capacitively loaded loops in a closed form by inverting the complex mutual inductance matrix. It is shown that retardation and higher order interactions have greater effect upon the attenuation of the arising backward wave than upon the phase change per element. The appearance of a forward wave with a phase velocity close to that of light is also shown.
Plasmonics: Metallic Nanostructures and Their Optical Properties IX, 2011
ABSTRACT Properties of split-ring metamaterials are governed by inter-element interactions. These... more ABSTRACT Properties of split-ring metamaterials are governed by inter-element interactions. These interactions lead to slow eigenmodes of coupling, which, due to their short wavelengths, are ideal candidates for the design of near-field manipulating devices. In this paper we explore the electric and magnetic coupling mechanisms in nano-U and nano-SRR dimers comprising of two identical nano-resonators arranged axially and twisted relative to each other by an arbitrary angle. We study theoretically the couplings in a periodic chain of nano-dimers for the frequencies from 100 to 300 THz. In our analytical model, the electric and magnetic couplings can be expressed through the self and mutual terms for the magnetic and electric field energy. In addition, we incorporate the effect of kinetic inductance due to the inertia of the electrons (noticeable as element dimensions approach 100nm or smaller). The resulting dependence of the electric, magnetic and the total coupling constants on the twist angle within the dimer obtained analytically is shown to agree with numerical simulations (CST Microwave Studio). Our approach should enable an effective design of metamaterial structures with desired properties and would be a useful tool in developing THz range manipulating devices based on propagation of slow waves by virtue of coupling.
Metamaterials, 2005
ABSTRACT We describe subwavelength properties of magnetic metamaterials designed to manipulate an... more ABSTRACT We describe subwavelength properties of magnetic metamaterials designed to manipulate and control the near field by employing magnetoinductive (MI) waves. MI waves owe their existence to the magnetic coupling between metamaterial elements. Magnetic field distributions and Poynting vector streamlines are used to visualise the diamagnetic and paramagnetic properties of metamaterials and to analyse working principles of MI waveguides and MI waveguide components.
Integrated Photonics Research, 2003
ABSTRACT The integration of magneto-optical devices enables cost and size reduction in optical co... more ABSTRACT The integration of magneto-optical devices enables cost and size reduction in optical commutication systems. Nonreciprocal phase shifters can be used to build polarization independent isolators and circulators. New photonic bandgap materials with high Faraday rotation make conventional magneto-optic device concepts suitable for PLC integration
Optics express, Jan 14, 2005
The current and field distribution in a 2D metamaterial consisting of resonant elements in a hexa... more The current and field distribution in a 2D metamaterial consisting of resonant elements in a hexagonal arrangement are found assuming magnetic interaction between the elements. The dispersion equation of magnetoinductive (MI) waves is derived with the aid of the direct and reciprocal lattice familiar from solid state theory. A continuous model for the current variation in the elements is introduced leading to the familiar wave equation in the form of a second order differential equation. The current distributions are shown to exhibit a series of spatial resonances for rectangular, circular and hexagonal boundaries. The axial and radial components of the resulting magnetic field are compared with previously obtained experimental results on a Swiss Roll metamaterial with hexagonal boundaries. Experimental and theoretical results are also compared for the near field image of an object in the shape of the letter M followed by a more general discussion of imaging. It is concluded that a ...
Accurate calculation of guided modes is one of the principal tasks of numerically simulating inte... more Accurate calculation of guided modes is one of the principal tasks of numerically simulating integrated optical devices. Our recently proposed 'wave-matching-method' for dielectric waveguides with rectangular and piecewise constant refractive index profiles is based on expansions of the electromagnetic field into functions with harmonic and exponential dependence on the transverse coordinates. Local expansions for regions with constant permittivity are joined by minimizing a least squares expression for the remaining misfit at the discontinuity lines. We apply the wave-matching analysis to a number of more complex structures: a conventional, deeply etched two-waveguide coupler, an ARROW-waveguide, a three dimensional four-waveguide coupler and a three-waveguide coupler with multimode central rib.
Coupled mode theory is applied to an arrangement of three raised strip waveguides with a multimod... more Coupled mode theory is applied to an arrangement of three raised strip waveguides with a multimode central strip. We use semivectorial numerically computed modes of the three single isolated waveguides as a basis for a propagating supermode analysis of the entire structure. The pronounced polarization dependence of the raised strip guides allows for the design of a conveniently short polarization splitter. We discuss design guidelines and estimate the fabrication tolerances. The accuracy of the coupled mode approach is assessed by comparison with rigorously computed supermodes for comparable two waveguide couplers. Both types of structures indicate the limits in the applicability of the coupled mode model.
Photonic Crystal Materials and Devices X, 2012
ABSTRACT The transformation of 2-dimensional slab photonic crystal into 2-dimensional photonic gl... more ABSTRACT The transformation of 2-dimensional slab photonic crystal into 2-dimensional photonic glass was achieved by gradually increasing the sphere spacing and by randomising the lattice. The materials were prepared by assembling colloidal particles at the air/water interface using a Langmuir-Blodgett trough and the subsequent deposition on glass substrates. Highly ordered monolayers were obtained by using colloids of one size, while use particles of two different sizes and different partial concentrations allows to increase the spacing of the larger spheres and to randomize the lattice. Changes in the spheres arrangements result in a change of in-plane light propagation from band-like to hopping photon transport.
ABSTRACT Metamaterials acquire their functionality from the structuring of small building blocks,... more ABSTRACT Metamaterials acquire their functionality from the structuring of small building blocks, "artificial atoms". Understanding the nature of the resonance behavior of unit cells is crucial for designing a structure with desired properties. In this paper we study the resonant behavior of metallic nanoparticles in the region of hundreds of THz, including square-cross-section nanorods, split squares, and split rings. For a better understanding of the resonant behavior of plasmonic nanoparticles we investigated standing wave patterns of surface plasmon polaritons on nanoparticles of different shapes. Our numerical results (CST Microwave Studio) suggest that the resonant behavior of each of these particles is similar to that of periodic arrays of nanorods with specific lengths and periodicities. For the first time to our knowledge, the interaction of the gap edges of a split ring, previously described in terms of the self-capacitance, has been interpreted in terms of coupled plasmonic modes.