Diffraction theory of an open resonator embedded in a uniaxial medium

A two-dimensional diffraction theory of an open strip resonator embedded in a umaxially anisotropic medium is presented. Applying the modified Kirchhoff approximation and a Green's function technique, the problem is reduced to the solution of a system of two coupled, homogencous integral equations for the unknown field distributions on the mirrors. The eigenvalues of this system of integral equations are related to the characteristic (complex) frequencies of the modes of the open resonator by an implicit relationship. The eigenvalues as well as the corresponding characteristic frequencies are calculated numerically. From the characteristic frequency of a mode, its resonance frequency, its diffraction loss and its quality factor follow immediatedly. For various resonator configurations the influence of the orientation of the optical axis of the uniaxial medium on the properties of the modes is studied in detail.     

Guided waves in anisotropic media

This paper investigates the propagation of electromagnetic waves in a dielectric anisotropic medium containing conducting planes. A plane and rectangular waveguide is considered for certain particular cases of the orientation of the principal axis of the anisotropic medium relative to the waveguide coordinates. The dispersion equations for the propagation constants are deduced.In conclusion we thank D. A. Dobrotin for his advice.     

Distribution of the Field of Whispering-Gallery Modes in a Radially Nonuniform Two-Layer Cylindrical Dielectric Resonator

We study eigenmodes of a radially nonuniform two-layer cylindrical dielectric resonator bounded by two perfectly conducting planes at its ends. Formulas for the electromagnetic-field components of the modes and the characteristic equation of the resonator made of anisotropic dielectrics and immersed in an anisotropic medium are obtained. Resonators with various whispering-gallery modes are studied numerically in the 8-mm wavelength range. The distributions of the axial field component of the eigenmodes over the radial coordinate are given for various values of the radius, dielectric permittivity, and loss tangent of the inner layer of the resonator. The influence of the inner-layer parameters on the behavior of field distribution over the radius and on the spectral and energy characteristics of the resonator are analyzed. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 7, pp. 622–632, July 2008.     

Scalable Quantum Information Transfer between Individual Nitrogen-Vacancy Centers by a Hybrid Quantum Interface

We develop a design of a hybrid quantum interface for quantum information transfer(QIT),adopting a nanomechanical resonator as the intermedium,which is magnetically coupled with individual nitrogen-vacancy centers as the solid qubits,while capacitively coupled with a coplanar waveguide resonator as the quantum data bus.We describe the Hamiltonian of the model,and analytically demonstrate the QIT for both the resonant interaction and large detuning cases.The hybrid quantum interface aiiows for QIT between arbitrarily selected individual nitrogen-vacancy centers,and has advantages of the scalability and controllability.Our methods open an alternative perspective for implementing QIT,which is important during quantum storing or processing procedures in quantum computing.     

Efficiency of excitation of a quasioptical open resonator by a waveguide

We study theoretically and experimentally the efficiency of excitation of an open resonator by a waveguide. A two-dimensional model of a quasioptical two-mirror open resonator, which is excited through a coupling element in the form of an open end of a plane-parallel waveguide, is proposed. The field of the open resonator is represented as the superposition of Gaussian wave beams and its scattering on the coupling element is described by solving the problem of diffraction of waveguide waves and Gaussian wave beams on an open end of a flanged waveguide. Properties of the mirrors and the resonator loss are specified from physical considerations. The calculation results are compared with the experimental data, and a physical interpretation of the obtained results is offered. The factors which influence the efficiency of excitation of an open resonator are identified. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 52, No. 3, pp. 231–249, March 2009.     

表面等离激元在具有PT对称性的环谐振器中的传输

提出了具有PT对称性的金属-绝缘体-金属波导系统,由两个波导耦合一个环谐振器组成,环谐振器的上臂填充增益介质而下臂填充损耗介质。对表面等离激元在该系统的传输特性进行了研究,结果表明:通过平衡增益介质和损耗介质,PT对称性诱导的透明峰可以被清楚地看到,并且该透明峰具有反相位的特点。     

Low threshold gain metal coated laser nanoresonators

We introduce a low refractive index layer between the metal and the gain medium in metal-coated laser resonators and demonstrate that it can significantly reduce the dissipation losses. Analysis of a gain medium waveguide shows that for a given waveguide radius, the low index layer has an optimal thickness for which the lasing threshold gain is minimal. The waveguide analysis is used for the design of a novel three-dimensional cylindrical resonator that is smaller than the vacuum wavelength in all three dimensions and exhibits a low enough threshold gain to lase at room temperature.     

TM-mode coupling in anisotropic optical waveguides caused by periodic variation optic-axis direction

The problem of mode coupling caused by a small periodic variation of the opticaxis direction in an anisotropic optical waveguide is reduced to a pair of coupled differential equations and an expression for the coupling coefficient is given. For a periodically perturbed section of the waveguide the coupled-mode equations are solved subject to suitable boundary conditions, and the coupling between the forward TM mode and the backward TM mode is analysed. A perturbed section of an anisotropic waveguide acts as a frequency selective reflection filter for TM modes only.     

Transient radiation in an anisotropic magnetodielectric plate in a waveguide

We have considered transient radiation of a charged particle in an anisotropic magnetodielectric plate placed into a regular waveguide. It is assumed that the charged particle passes through the plate moving at a constant velocity perpendicularly to the waveguide axis. Wave equations and analytical expressions for transverse electric (TE) and transverse magnetic (TM) fields in different regions of the waveguide have been obtained. Energies of transient radiation of the moving particle have been calculated. The properties of transient radiation and Vavilov–Cherenkov radiation have been analyzed for the case of a rectangular waveguide. Energies of transient radiation have been calculated for the case of a “thin” plate in the waveguide, when the wavelength in the plate is much greater than the length of the plate.     

Separable equations for a cylindrical anisotropic elastic waveguide

A separable form of the equations of motion for a cylindrical anisotropic elastic waveguide of arbitrary cross-section is derived. From these the orthogonality relation for the modes of harmonic wave propagation in the waveguide is readily derived.     

Transferring and Bounding Single Photon in Waveguide Controlled by Quantum Node Based on Atomic Ensemble

We study the scattering process of photons confined in a one-dimensional optical waveguide by a laser controlled atomic ensemble. The investigation leads to an alternative setup of quantum node controlling the coherent transfer of single photon in such one dimensional continuum. To exactly solve the effective scattering equations by using the discrete coordinate approach, we simulate the linear waveguide as a coupled resonator array at the high energy limit. We generally calculate the transmission coefficients and itsvanishing at resonace reflects the good controllability of our scheme. We also show that there exist two bound states to describe the localize photons around the cavity.     

Slow propagation of plasmonic modes in a symmetrical waveguide containing anisotropic metamaterial

We study the slow propagation of plasmonic modes in a three-layer symmetric waveguide with anisotropic metamaterial claddings and a dielectric core. The dispersion equations for symmetric and anti-symmetric plasmonic modes are derived, and a graphic method is used to verify the zero-group-velocity point on the dispersion curves. Simulation results show the influences of signs of tensors and anisotropy of metamaterial on trapped plasmonic modes.     

Interaction between a BSCCO-type intrinsic Josephson junction and a microwave cavity

The electrical behavior of anisotropic BSCCO single crystals is modeled by mutually coupled long Josephson junctions. We show that although the fluxons in the different layers do not a priori prefer the in-phase motion desired for many potential applications it is possible to induce such behavior by coupling the system to a high-Q resonator with a resonance frequency corresponding to fluxon in-phase motion. The resulting model is a set of coupled non-linear partial differential equations. By direct numerical simulations we have demonstrated that the qualitative behavior of the combined stacked long Josephson junctions and cavity system can be understood on the basis of the general concepts of nonlinear oscillators interacting with a resonator. For some region of the parameter space it is possible to reach the desired synchronous state, making the system potentially suitable for applications. We also look at the different dynamical states defined by different fluxon dynamical states in combination with different cavity properties.     

Design of an acoustic bending waveguide with acoustic metamaterials via transformation acoustics

Transformation acoustics is employed to design an acoustic bending waveguide. A two-dimensional square area with anisotropic and homogeneous material properties is transformed into a fan-shaped area with anisotropic and inhomogeneous material properties to rotate the direction of beam propagation. An alternating layered structure is considered to approximate a medium with anisotropic material properties. From the calculation results, the transformation medium can be realized by an alternating layered structure consisting of water and fluid with negative mass density. We propose that an acoustic metamaterial composed of three layers in water background can be designed to replace negative mass density fluid. The effective mass density and bulk modulus of the system that is composed of the acoustic metamaterial and water are dependent on the incident frequency and the geometric size of the acoustic metamaterial. We tune the geometric size of the acoustic metamaterial to approach the corresponding mass density distribution of the negative mass density fluid at a specific frequency. Thereby, the acoustic bending waveguide designed by using transformation acoustics can be achieved by the acoustic metamaterials.     

Proposed solar energy conversion and storage system using a nano-ring in an array waveguide

We propose the new solar energy conversion and storage system using the array waveguide. It can be used to generate and store solar energy within the nano-array waveguide system. The system consists of micro- and nano-ring resonators incorporating a Mach Zhender Interferometer (MZI) that can be integrated into a single system. The large bandwidth signal, i.e. white light, is generated using a soliton pulse in a Kerr-type nonlinear medium propagating within a micro-ring resonator system. The control light concept is applied using a nano-waveguide incorporating an MZI, whereas the incoherent light is filtered being coherence, which is amplified and stored within the system. The white light can be re-generated using the stored coherent light pulse. Furthermore, the combination of signals is formed by the array waveguide, which is allowed to generate the huge amount of solar energy output.     

Whispering gallery mode profiles in a coated microsphere

The properties of whispering gallery modes (WGM) of a microsphere can be tailored by coating the resonator with a thin film. If the coating has a higher refractive index than the microsphere core, the resulting structure will have a configuration which has similarities both with a classical WGM resonator and with a planar waveguide. By choosing the film thickness and refractive index we can tailor the degree of confinement of the WGMs inside the sphere core, coating and surrounding medium, which will in turn influence the WGMs contact with its surroundings. We present a study of the effect of the coating on the WGM mode profiles in particular of a silicon coating on a silica sphere.     

Two-dimensional problems of determination of mode spectra of anisotropic diffusion waveguide

Spectral problems of determination of the mode propagation constants and electromagnetic fields of a two-dimensional optical waveguide with a diagonal permittivity tensor are formulated mathematically and solved numerically. The results for some refractive-index profiles in the isotropic case are in good agreement with the solutions of other authors. A specific calculation is made for an anisotropic diffusion waveguide. Some physical aspects of the obtained equations are discussed.     

Analysis of a second-order polarization-independent filter made of a single ring resonator and a Sagnac interferometer

A novel second-order polarization-independent filter made of a single ring resonator and a Sagnac interferometer (SRRSI) is proposed, and its filtering characteristics are investigated. By using birefringence in waveguide, a single ring resonator can be used to synthesize a filter with second-order response. Analytical formulas are derived for characteristics of the SRRSI varied with waveguide parameters, such as the coupling coefficient; and the critical condition of a second-order Butterworth filter is given. The influence of loss in the ring resonator is also analyzed.     

Resonant modal conversion in a two-mode waveguide

We characterize a system consisting of a two-mode waveguide coupled to a single-mode microring resonator possibly presenting a nonlinear response of Kerr type. By using the scattering parameter formalism extended to the multimode domain, we show that in the linear regime and for an ideally transparent medium, each resonance of the system can be exploited to perform complete even-to-odd (respectively, odd-to-even) modal conversion. Moreover, when the Kerr nonlinearity is effective, the microring enables a power-dependent modal switching mediated by phase bistability. Thanks to its mode-processing capabilities, this configuration is suitable to find application as a functional building-block in mode-division multiplexing (MDM) photonic integrated circuits.     

Coupling Losses and Discrimination of Annular Waveguide Laser Resonators

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