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The purpose of this paper is to discuss two‐dimensional electromagnetic diffraction by a finite set of parallel nonlinear rods (optical Kerr effect). To point out the versatility of this approach, a nonlinear (Kerr‐effect) finite crystal is considered.

In this paper, a new route for obtaining the scattered field by nonlinear obstacles is proposed. The basic idea consists in simulating the real incident field (e.g. plane waves) by a virtual field emitted by an appropriate antenna, located in a meshed domain, and encompassing or lying above the obstacles. This latest problem is then solved by a finite element method that is well suited to take into account the material inhomogeneities due to the nonlinearity of the permittivity.

The transmission through a finite Kerr crystal doped by a microcavity is given and a resonant wavelength is obtained. At this resonant wavelength, it is shown that the nonlinearity has a large influence on the behaviour of the electromagnetic wave.

Introducing the concept of virtual antenna, the paper proposes a rigorous treatment of the scattering of an electromagnetic wave by a bounded nonlinear obstacle of arbitrary shape.

This paper concerns the study of non‐linear effects in optical fibres with a core made of a Kerr type medium. The aim is to propose an algorithm to find spatial solitons, i.e. solutions with a harmonic behaviour in time and along the fibre but with a field distribution in the cross‐section corresponding to a self‐trapped propagation of the electromagnetic field.

The field is supposed to be harmonic in time and along the direction of invariance of the fibre but inhomogeneous in the cross‐section. This modifies the refractive index profile of the fibre (a step‐index one in this study). A scalar model of the fibre, together with the finite element method (that is well suited to deal with inhomogeneous media), is used and a new iterative algorithm is proposed to obtain the non‐linear solutions. An adaptive meshing is necessary to guarantee the accuracy of the model.

The new algorithm converges to self‐coherent solutions that are different from those obtained via a fixed power algorithm. The equivalents both of a fundamental mode and of a second order mode are studied.

The approach acknowledges the findings of the previously known spatial solitons (with a slight modification of the algorithm) together with a new family of solutions. It opens a new field of investigation to understand this whole family of non‐linear solutions as it shows that only a small part of them was known up to now.

The areal (surface area density of bits) storage density of magnetic hard disks is continually increasing, with typical available commercial storage densities being around 10Gbits/in². It is predicted that densities in excess of 40Gbits/in² will be possible before the year 2003. A number of key issues arise from this development, such as the need to determine and control accurately the dynamic flying height (z‐axis) of the read‐write head, which is affected by the apparent distortion of the disk surface due to rotation‐induced disk resonance. As a result of the increasing storage density the positional control of the head in the plane of the disk (x‐y plane) also becomes more critical. This paper deals generally, but with a particular emphasis on optical and piezoelectric sensors used in our laboratory for characterisation of storage media and systems.

The purpose of this paper is to obtain the nonlinear Schrodinger equation (NLSE) numerical solutions in the presence of the first-order chromatic dispersion using a second-order, unconditionally stable, implicit finite difference method. In addition, stability and accuracy are proved for the resulting scheme.

The conserved quantities such as mass, momentum and energy are calculated for the system governed by the NLSE. Moreover, the robustness of the scheme is confirmed by conducting various numerical tests using the Crank-Nicolson method on different cases of solitons to discuss the effects of the factor considered on solitons properties and on conserved quantities.

The Crank-Nicolson scheme has been derived to solve the NLSE for optical fibers in the presence of the wave packet drift effects. It has been founded that the numerical scheme is second-order in time and space and unconditionally stable by using von-Neumann stability analysis. The effect of the parameters considered in the study is displayed in the case of one, two and three solitons. It was noted that the reliance of NLSE numeric solutions properties on coefficients of wave packets drift, dispersions and Kerr nonlinearity play an important control not only the stable and unstable regime but also the energy, momentum conservation laws. Accordingly, by comparing our numerical results in this study with the previous work, it was recognized that the obtained results are the generalized formularization of these work. Also, it was distinguished that our new data are regarding to the new communications modes that depend on the dispersion, wave packets drift and nonlinearity coefficients.

The present study uses the first-order chromatic. Also, it highlights the relationship between the parameters of dispersion, nonlinearity and optical wave properties. The study further reports the effect of wave packet drift, dispersions and Kerr nonlinearity play an important control not only the stable and unstable regime but also the energy, momentum conservation laws.

The purpose of this paper is to improve the modeling accuracy of the magnetostrictive hysteretic characteristics by introducing hysteresis energy instead of pinning energy in the assembled domain structure model (ADSM).

First, the magnetostrictive characteristics and the domain movement process in an electrical steel sheet are measured and observed. The reasons for the influence of stress on magnetostriction are discussed on the mesoscopic level. Second, the ADSM model using the hysteresis energy is investigated to estimate the influence of external stress. Finally, the simulation results of the modified ADSM model are compared with the experimental data under the same calculation conditions.

The results show that the improved model not only explains the cause of hysteresis clearly from the perspective of the magnetic moment but also improves the modeling ability of magnetostrictive hysteretic.

The magnetostriction in electrical steel lags behind the external magnetic field, and it is significant for reducing core vibration to estimate the magnetostrictive hysteretic property accurately. This paper proposes an effective approach to model the hysteretic characterization of magnetostriction.

The purpose of this paper is to introduce an approach for m‐valued classical and non‐classical (reversible and quantum) optical computing. The developed approach utilizes new multiplexer‐based optical devices and circuits within switch logic to perform the required optical computing. The implementation of the new optical devices and circuits in the optical regular logic synthesis using new lattice and systolic architectures is introduced, and the extensions to quantum optical computing are also presented.

The new linear optical circuits and systems utilize coherent light beams to perform the functionality of the basic logic multiplexer. The 2‐to‐1 multiplexer is a basic building block in switch logic, where in switch logic a logic circuit is implemented as a combination of switches rather than a combination of logic gates as in the gate logic, which proves to be less‐costly in synthesizing wide variety of logic circuits and systems. The extensions to quantum optical computing using photon spins and the collision of Manakov solitons are also presented.

New circuits for the optical realizations of m‐valued classical and reversible logic functions are introduced. Optical computing extensions to linear quantum computing using photon spins and nonlinear quantum computing using Manakov solitons are also presented. Three new multiplexer‐based linear optical devices are introduced that utilize the properties of frequency, polarization and incident angle that are associated with any light‐matter interaction. The hierarchical implementation of the new optical primitives is used to synthesize regular optical reversible circuits such as the m‐valued regular optical reversible lattice and systolic circuits. The concept of parallel optical processing of an array of input laser beams using the new multiplexer‐based optical devices is also introduced. The design of regular quantum optical systems using regular quantum lattice and systolic circuits is introduced. New graph‐based quantum optical representations using various types of quantum decision trees are also presented to efficiently represent quantum optical circuits and systems.

The introduced methods for classical and non‐classical (reversible and quantum) optical regular circuits and systems are new and interesting for the design of several future technologies that require optimal design specifications such as super‐high speed, minimum power consumption and minimum size such as in quantum computing and nanotechnology.

Microribbon with meander type based on giant magnetoimpedance (GMI) effect has become a research hot spot due to their higher sensitivity and spatial resolution. The purpose of this paper is to further optimize the line spacing to improve the performance of meanders for sensor application.

The model of GMI effect of microribbon with meander type is established. The effect of line spacing (Ls) on GMI behavior in meanders is analyzed systematically.

Comparison of theory and experiment indicates that decreasing the line spacing increases the negative mutual inductance and a consequent increase in the GMI effect. The maximum value of the GMI ratio increases from 69% to 91.8% (simulation results) and 16.9% to 51.4% (experimental results) when the line spacing is reduced from 400 to 50 µm. The contribution of line spacing versus line width to the GMI ratio of microribbon with meander type was contrasted. This behavior of the GMI ratio is dominated by the overall negative contribution of the mutual inductance.

This paper explores the effect of line spacing on the GMI ratio of meander type by comparing the simulation results with the experimental results. The superior line spacing is found in the identical sensing area. The findings will contribute to the design of high-performance micropatterned ribbon with meander-type GMI sensors and the establishment of a ribbon-based magnetic-sensitive biosensing system.

The desirability of electronic document delivery systems has been argued for years and the reasons for the slow progress of the idea are discussed. An explanation of the technical background is provided followed by some examples of electronic means of information distribution such as facsimile and disc‐based systems. Some experimental projects are described and the article concludes with a description of document image processing systems used for business purposes which have a number of features in common with delivery systems.