Using the Finite Element Method to Solve Coupled Wave Equations in Volume Holograms

Abstract

Galerkin's finite element method has been used to solve the coupled wave equations in a volume hologram. The expressions which transform the coupled wave equations into a matrix equation are given. Numerical examples show that the method is very accurate and efficient.     

Transfer characteristics and propagation effects of a multi-resonance ring resonator-based optical device

Abstract

We describe the linear and nonlinear optical transfer characteristics of a multi-resonance device consisting of two optical ring resonators coupled one to the other and to an optical waveguide. The propagation effects displayed by the device are compared with those of a sequence of fundamental ring resonators coupled to a waveguide.     

The vibration and pull-in mechanism of two coupled elastically restrained beams assembly subjected to electrostatic force

ABSTRACT

The novel model of the coupled beam-type electrodes with elastic roots, subjected to the AC and DC voltages is constructed. The exact critical pull-in voltage of the two coupled elastically restrained beams with size effect is presented. The analytical method of the general system subjected to the AC and DC voltages simultaneously is presented. The characteristic mechanism of coupled vibration is investigated.     

Effects of coherence and polarization on the coupling of stochastic electromagnetic beams into optical fibers: errata

We correct a mistake in the expression of the coupled power into an optical fiber that led to some erroneous conclusions in Opt. Lett. 34, 2829 (2009) and J. Opt. Soc. Am. A 26, 2452 (2009).     

Coupled Surface Plasmons at 3·391 μm

Abstract

Using 3·391 μm wavelength radiation to excite surface plasmons means that the conventional dimensional constraints imposed upon the dielectric thickness required for coupled surface plasmons is relaxed. Results are presented and analysed for coupled surface plasmons using silver layers spaced by a variable air gap of several micrometres thickness. Adjusting the air gap allows the determination of the dispersion curve for the coupled plasmons as a function of gap thickness down to a gap of about 5 μm.     

Optimization of an optical filter with a square-shaped passband based on coupled microcavities

Abstract

An approach using simple analytical theory has been developed for the design of multilayered spectral optical filters based on coupled microcavities. The method has been applied to find the parameters of the optimal structure, providing a near square-shaped transmission band. The case of normal and oblique incident light has been considered. It is shown that the situation corresponding to the weak coupling-strong coupling threshold for coupled cavity modes is optimal for achieving a square-shaped transmission band.     

Quantization of coupled modes propagation in integrated optical waveguides

Abstract

A quantum mechanical analysis of the propagation of coupled modes in integrated optical waveguides is given. The modal orthonormalization property on a cross-section of an optical waveguide, the vector structure of the guided optical modes and the reversal-time symmetry are taken into account to derive the quantum momentum operator and Heisenberg's equations giving a quantum-consistent formulation of the coupled mode propagation as a function of forward and backward creation and annihilation operators.     

Optical solitons in a new type of coupled nonlinear Schrödinger equations

Abstract

We consider a new type of integrable coupled nonlinear Schrödinger (CNLS) equations proposed by Park and Shin [1999, Phys. Rev. E, 59, 2372]. Using the Ablowitz-Kaup-Newell-Segur method, we construct the Lax pair for simultaneous propagation of four fields in the new type of CNLS equations. The explicit form of soliton solutions are derived using the Hirota bilinear method.     

Coupled vertical microcavities

A design is proposed for a device consisting of two optically coupled vertical microcavities. It is shown that interaction between two localized optical modes in the coupled microcavities induces mode splitting. The feasibility of using this design to develop optoelectronic devices is analyzed. Pis’ma Zh. Tekh. Fiz. 23, 74–78 (February 12, 1997)     

Optical solitons for cascaded system: Jacobi elliptic functions

Abstract

In this work, the coupled NLSE is studied that appears in a cascased system. Exact solutions of this coupled system acquire by using Jacobi elliptic functions. The presented system will be studied with two forms of nonlinearity. The forms are kerr law and power law. Dark, bright, singular solitons and Jacobi elliptic solutions will be acquired. We present constraint conditions for the existence of obtained solitons. Our obtained solitons will be controlled by changing the diffraction coefficients.     

Matrix theorems of multiconductor transmission lines

Abstract

The purpose of this article is to present three matrix theoremes pertaining to the analysis of electrical multiconductor transmission lines. In principle, the formulations are also applicable to coupled mechanical systems.     

Coherent Atomic Excitation in a Cavity. I. Low Density

Abstract

We present a procedure for treating coherent selective excitation (and subsequent ionization) of atomic vapour in a radiation-filled cavity. Specifically, we describe a technique for solving the coupled Maxwell-Bloch equations for atoms in a one-dimensional cavity by means of a spatial quasi-Fourier expansion that introduces a sequence of increasing spatial harmonics for atomic populations and coherences. We discuss the resulting coupled equations and present examples of solutions for a simple model of stationary and moving two-state atoms in the limit of very low density. The atomic excitation exhibits a travelling wave behaviour, but with significant modulation.     

Recursive exact ray trace equations through the foci of the tilted off-axis confocal prolate spheroids

Abstract

Simple, exact ray trace equations are derived for a general ray propagating through the foci of tilted, coupled, confocal spheroids. In this off-axis optical system, there does not necessarily exist a (real) ray for which the paraxial approximation applies.     

Coupled Cavity Mode-locking Using Nonlinear Amplitude Modulators

Abstract

A straightforward analysis of the process by which nonlinear amplitude modulators in coupled cavities can lead to enhanced mode-locking is presented. The application of the theory is demonstrated by using second-harmonic generation in an external cavity to mode-lock a Nd:YAG laser yielding 30 ps pulses in a Q-switched and mode-locked pulse train.     

Can the kicked top be realized?

Abstract

Collections of identical two-level atoms can give rise to (quantum) chaotic behaviour if non-resonantly coupled to a resonator mode and periodically driven. Observation of such chaos would require a new generation of experiments on microwave superradiance, or optical variants thereof which would exploit the strong coupling characteristic of very small cavities. Similarly, collections of identical three-level atoms non-resonantly coupled to two cavity modes could provide ‘SU(3) laboratories’, capable of realizing the semiclassical and classical limits of SU(3) dynamics, both integrable and chaotic. Some of the more interesting modes of behaviour of such systems are discussed.     

Spiral wave self-organization in a coupled-map lattice: Hydrodynamic scaling

The dimensions of spiral waves reveal a scaling correspondence with the diffusion length, which is a fundamental unit of length in a coupled map lattice. Pis’ma Zh. Tekh. Fiz. 25, 89–94 (February 12, 1999)     

Mixed-dimensional modeling by means of solid and higher-order multi-layered plate finite elements

Abstract

Solid and higher-order plate finite elements are coupled for the analysis of composite structures by means of the Arlequin method. Plate and solid elements are derived by a unified formulation and they do not depend on the number of nodes. Higher-order and zig-zag plate elements are easily formulated regardless the approximation order along the through-the-thickness direction. Composite and sandwich plates are investigated. Multi-model solutions are assessed towards equivalent mono-model ones and commercial finite element software results. The numerical investigation shows that higher-order plate finite elements and solid ones are successfully coupled.     

N-level Atom Interacting with Single-mode Radiation Field: An Exactly Solvable Model with Multiphoton Transitions and Intensity-dependent Coupling

Abstract

We study the dynamics of an N-level atom coupled in a lossless cavity to a single-mode near-resonant quantized field. The atomic levels are coupled by the multiphoton transitions and the coupling constants between the field and the atomic levels are supposed to be intensity dependent. We find the exact solution for the state vector describing the dynamics of the atom-plus-field system. As an illustration we use the model for studying (i) the time evolution of the atomic occupation probability with the initially coherent field and (ii) the light squeezing, when the cavity field is initially in the vacuum state and the atom is prepared in the atomic ‘coherent state’ (a superposition of atomic states).     

Switching and self-trapping dynamics of bose-Einstein solitons

Abstract

We investigate the dynamics of two weakly coupled Bose condensates in long cigar-shaped traps. The Bose condensates are characterized by attractive mean-field interaction and consequently can be studied in terms of bright solitons. We exploit the analogy with directional fibre couplers in nonlinear fibre optics to uncover interesting dynamical regimes like switching of condensates from one trap to another and self-trapping of condensates. We also discuss the analogy between two weakly coupled Bose condensates and the Josephson junction in superfluids and superconductors.     

The Jaynes-Cummings Model with a q Analogue of a Coherent State

Abstract

In this paper we study the time evolution of the atomic inversion of the two-level atom which is coupled to the q analogue of a single mode of the bosonic field. The q field under consideration is supposed to be prepared initially in the q analogue of Glauber's coherent state. We find that q deformation of Heisenberg algebra may correspond to some effective nonlinear interaction of the cavity mode.