Coupled wave theory for volume holograms recorded by two strong andN weak plane waves

A set ofN + 2 coupled differential equations is derived for the amplitudes of the waves, and an analytic solution is presented for a simple case. The effect of the weak beams on the maximum conversion efficiency between the strong waves is discussed.     

Two-dimensional stability of large amplitude langmuir waves and solitons

The two-dimensional stability of nonlinear wave and soliton solutions of the exponentially nonlinear Schrödinger equation is examined. All stationary entities are unstable to two-dimensional perturbations. It is found that the saturable nonlinearity decreases growth rates in comparison with the small amplitude limit.     

Enhanced angular selectivity in volume holograms with speckle reference waves

A speckle-multiplexing scheme with enhanced angular selectivity for holographic storage is proposed. Angular selectivity in the proposed holographic storage system is theoretically and experimentally investigated. We find the effect of speckle reference wave on angular selectivity strongly depends on the techniques to perform multiplexing for holographic storage. Angular selectivity of a holographic storage system can be effectively enhanced as long as angular deviation of reading wave induces a lateral displacement of the speckle pattern on the hologram plane. When angular deviation of reading wave only induces a speckle wavefront tilt on the hologram plane, the speckle wave is not helpful to enhance the angular selectivity and the angular selectivity becomes to depend on material thickness (Bragg condition) only.     

Elastic scattering amplitude of a polarized electron in an arbitrary plane wave field

The elastic scattering amplitude of a polarized electron in an arbitrary plane wave electromagnetic field is obtained by using the method of dispersion relations. Superposition of a constant crossed field and a plane monochromatic wave of elliptic polarization is considered a particular case of giving the field. An anomalous magnetic moment is obtained for the electron in the mentioned field as are also relative contributions to the anomalous magnetic moment due to the transition into the intermediate state with and without spin turnover.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 69–75, October, 1990.     

Localized one-dimensional theory for volume holograms

Coupled partial differential equations are derived, consistent with localized use of one-dimensional theory in a thin volume hologram, from modifications to both one-dimensional and two-dimensional theory. The approximations inherent in the model and the range of validity of the solution are discussed.     

Ie transmission properties of stratified chiroferrite media with obliquely incident plane wave

A parameter study of electromagnetic wave propagating through the air-chiro ferrite inter face and through a chiro ferrite slab is presented, and such bianisotropic medium can be made from chiral and gyrotropic ferrite materials artifically. The partial differential equations of the fourth order defining the field components E_y and H_y in chiroferrite are derived. The influence of different constitutive parameters on the transmission coefficients and refraction angles of transmitted fields are demonstrated. The results show that chirality causes strong effect of energy conversion between mode 1 and 2.     

Spectral responses of gyrotropic chiral sculptured thin films to obliquely incident plane waves

Gyrotropic chiral sculptured thin films (STFs) exhibit optical activity due to their structural chirality, local anisotropy, and magneto-optic gyrotropy. We adapted two algorithms for nongyrotopic chiral STFs to investigate the circular-polarization-sensitivity of gyrotropic chiral STFs to incident plane waves. The impacts of gyrotropy and oblique angles of incidence on the reflectances and the transmittances were examined, and several conclusions drawn. In particular, we found that the incorporation of gyrotropy results in a blueshift of the Bragg regime.     

A general solution for two-dimensional volume holograms

We inv estigate the problem in which a volume hologram is produced by two waves of arbitrary amplitude and phase distribution (the only restriction being that they must obey the rules of geometrical optics), and the developed hologram is illuminated by one of the waves having the same phase distribution but not necessarily the same amplitude distribution. Coupled partial differential equations are derived and solved in the form of an infinite series valid for both transmission and reflection holograms. For transmission holograms a simple approximate solution is given for the amplitude of the reconstructed wave in the immediate vicinity of the input surface.     

Analysis of the effect of blocking mass at corner interface of two plates at arbitrary angles on transmission of plane bending waves

Vibration energy transmission at corner interface of two infinite plates rigidly jointed at arbitrary angles was studied by wave approach so as to investigate the effect of blocking mass used for reducing plane bending wave transmission.Two local coordinate sys- tems were introduced and six new non-dimensional coefficients implying corresponding ratio governing characteristic impedances of plates or blocking mass were introduced to simplify for- mulations of transmission and reflection coefficients.Five samples were tested in experiment. Discussions were carried out based on the comparison between prediction and experiment in terms of insertion loss.It is concluded that blocking mass at corner interface acts like a\"low- pass filter\",effective for vibration attenuation above certain frequency.The value of TL and IL in\"attenuation band\"depends mainly on mass per unit length and band width of\"attenuation band\"on mass moment of inertia per unit length of the blocking mass.     

A power conservation theorem for volume holograms

The two-beam coupled wave analysis of volume holograms given by Solymar, which is a two-dimensional generalisation of Kogelnik's formulation, is extended further to provide an alternative treatment of ‘d.c.’ dephasing effects, and the resulting coupled wave equations are shown to contain an implicit power conservation theorem.     

Scattering of plane guided waves obliquely incident on a straight feature with uniform cross-section

A frequency-domain finite element (FE) method is presented for modeling the scattering of plane guided waves incident on an infinitely-long, straight feature with uniform cross-section in a planar host waveguide. The method utilizes a mesh of 2-dimensional finite elements with harmonic shape functions in the perpendicular direction. The model domain comprises a cross-section through the feature and short lengths of the adjoining host waveguide. A spatial frequency equal to the wavenumber of the desired incident mode multiplied by the sine of the desired incidence angle is prescribed for the element shape functions. An integral representation of the incident mode is used to determine a suitable system of harmonic forces to uniquely excite that mode. These are applied at nodes through the thickness of the host waveguide on one side of the feature. The displacement field is measured at nodes through the thickness of the host waveguide on either side of the feature and decomposed into reflected and transmitted modes. The cases of guided wave transmission in a featureless waveguide and the reflection of guided waves from a free-edge are examined as validation cases. Finally, the results for transmission at an adhesively-bonded stiffener are presented and compared with experimental measurements.     

球面波条件下体全息存储的衍射特性分析

从理论上推导了球面波作为参考光和读出光时体全息存储的相对衍射效率和晶体旋转角度之间的关系,对得到的衍射效率的理论公式进行了数值模拟,并且对模拟的结果进行了分析。结果表明,球面波系统的存储容量更高,角度选择性更好,并且有利于系统的小型化。     

Transverse magnetic scattering of two incident plane waves by a dielectric coated cylindrical reflector

Scattering characteristics of two plane waves are investigated for a circular cylinder covered by a dielectric substance. Fields are assumed to be transverse magnetic (TM) and represented in an exponential series form. The diffracted radiations are found by applying the boundary conditions to the wave functions. The wave transformation method and the orthogonality of the exponential functions are respectively employed to obtain an infinite series in the solution. Numerical results are evaluated by reducing the infinite series to a finite number of terms and comparing estimates with the single plane wave scattering situation.     

Reflection and transmission of plane electromagnetic waves in uniaxial bianisotropic materials

Electromagnetic waves in the most general linear reciprocal uniaxial media are considered. The theory is appropriate for novel reciprocal microwave materials which have properties of chiral composites and omega structures (or both) and can be modeled by uniaxial bianisotropic constitutive relations. Field coupling terms in the media equations are assumed to be the most general uniaxial dyadics with symmetric and antisymmetric components. Plane eigenwaves in unbounded media are studied and the theory of reflection and transmission in plane layers is constructed.