共查询到20条相似文献,搜索用时 31 毫秒
1.
S.N. Bajpai 《Journal of magnetism and magnetic materials》1985,50(1):59-63
An investigation of the effect of the direction of a dc biasing field on the magnetostatic volume wave delays in YIG sandwiched between two ground planes has been made. Specifically, the magnetic field has been assumed to be arbitrary in three planes: (a) forward volume wave to backward volume plane; (b) forward volume wave to surface wave plane; (c) backward volume wave to surface wave plane. A general dispersion relation has been derived. The numerical results indicate that delays can be controlled by the direction of the dc magnetic field. The effect of the thickness of the dielectric on the delay characteristics of magnetostatic backward volume waves has also been studied. The present study shows that a suitable filter can be designed, whose bandwidth may be varied by rotating the direction of the magnetic field. 相似文献
2.
A. S. Kindyak 《Technical Physics》1999,44(6):715-717
A theoretical analysis is made of the propagation of a nonlinear surface magnetostatic wave in a planar ferrite semiconductor
structure as a function of the carrier concentration in the semiconductor layer. It is shown that for certain concentrations
the surface magnetostatic wave is unstable with respect to longitudinal perturbations and may propagate perpendicular to the
magnetic field in the form of solitons.
Zh. Tekh. Fiz. 69, 119–121 (June 1999) 相似文献
3.
The four-magnon instability of magnetostatic surface waves (MSSWs) in yttrium iron garnet epitaxial films is investigated
experimentally. It is shown that four-magnon instability for MSSWs with wave numbers 30–600 cm−1 is a decay instability and develops for values of the wave magnetization close to the threshold level for second-order parametric
instability of a homogeneous transverse pump wave. When the supercriticality of the MSSW power is 15–20 dB, the generated
parametric spin waves themselves become unstable with respect to the four-magnon interaction, so that kinetic instability
develops in the film. It is shown that the pump signal transmitted through the signal and the length of the “nonlinear” part
of the film, where a MSSW is capable of exciting parametric spin waves, increase as the pump power is increased.
Fiz. Tverd. Tela (St. Petersburg) 38, 330–338 (February 1997) 相似文献
4.
G. A. Melkov A. A. Serga A. N. Slavin V. S. Tiberkevich A. N. Oleinik A. V. Bagada 《Journal of Experimental and Theoretical Physics》1999,89(6):1189-1199
A solution is obtained for the general problem of the nonstationary interaction of backward volume magnetostatic waves in
films of yttrium-iron garnet with local parametric pumping. In the case of a large pump region, l≫λ, where λ is the wavelength of the backward volume magnetostatic waves, the problem reduces to a system of truncated equations for
two packets of counter propagating waves. In the opposite case, l<λ, the exact problem of parametric interactions of the eigenmodes of a ferrite film (both counterpropagating and in the same
direction) is solved numerically. Both cases are studied experimentally and good qualitative and quantitative agreement is
obtained with the theory. For the first time, the reversal of a wave front and the time reversal of the shape of backward
volume magnetostatic wave pulses are observed and a change in the propagation time for the peak of the signal pulse and a
reduction in its width owing to pumping are recorded. Two operating regimes are identified for a nonstationary parametric
backward volume magnetostatic wave amplifier with local pumping, which differ in the ratio of the duration of the pump pulse
to the transit time for the wave through the local pump region, and the effect of the parametric excitation of two-dimensional
spin waves on the interaction of backward volume magnetostatic waves with a local nonstationary parametric pump is determined.
Zh. éksp. Teor. Fiz. 116, 2192–2211 (December 1999) 相似文献
5.
The field distribution of magnetostatic surface and volume waves as they propagate at an arbitrary angle to a constant field
in a tangentially magnetized ferromagnetic slab (Damon-Eschbach waves) is investigated. Snapshots of the magnetic field lines
of the wave are constructed. The variation of the magnetic field distribution with thickness is qualitatively identified for
a volume wave as it propagates at an angle equal to the cutoff angle of the surface wave, as a result of which the sinusoidal
profile of the wave over thickness almost discontinuously acquires an additional phase difference.
Zh. Tekh. Fiz. 69, 82–86 (January 1999) 相似文献
6.
S. L. Vysotskii G. T. Kazakov Yu. A. Filimonov A. V. Maryakhin 《Technical Physics》1998,43(7):834-845
The influence of exchange coupling of layers on the propagation of magnetostatic dipole volume waves in normally and tangentially
magnetized two-layer epitaxial ferrite structures is investigated. It is shown that the indicated influence is manifested
in the form of dynamic spin pinning effects on the interlayer boundary and formation of a common dipole-exchange wave spectrum
for the entire structure. In this case, at the synchronism frequencies of the dipole and exchange waves the losses of the
dipole waves grow and anomalous segments appear in the dispersion. In films magnetized in the “hard” direction relative to
the axis of normal uniaxial surface anisotropy the magnetostatic dipole volume waves can interact resonantly with the surface
spin waves supported by the boundaries with pinned spins.
Zh. Tekh. Fiz. 68, 97–110 (July 1998) 相似文献
7.
A. Yu. Annenkov S. V. Gerus 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(10):1355-1356
A special direction of the wave vector was found for volume magnetostatic waves (MSWs) that coincides with the cutoff angle
for surface MSWs; when crossing this direction, the field configuration for MSWs with small wavenumbers changes sharply. It
is shown that this direction corresponds to the maximum asymmetry of magnetostatic potential distribution over the film depth
and the largest wave penetration depth into the film bulk from the surface. This effect occurs also for volume MSWs propagating
in a wave channel. 相似文献
8.
The dispersion relation of magnetostatic waves tangentially magnetized to saturation ferrite film, with a “magnetic wall” condition (tangential component of microwave magnetic field is equal to zero) on one of the film surface and with a metal condition on the opposite surface is analyzed. The dispersion characteristics show that unidirectional magnetostatic waves appear in this structure: they can transfer energy in one direction only and fundamentally cannot transfer energy in the opposite direction. The dispersion-free propagation of magnetostatic waves also is possible in the structure in a wide frequency interval. 相似文献
9.
不均匀磁场中的静磁波传播和导波光衍射理论 总被引:2,自引:1,他引:1
理论研究了不均匀静磁场对静磁体波传播和导波光布拉格衍射特性的影响。计算表明,在场强不均匀磁场中,静磁体波的振幅有所增加,从而可以明显提高导波光的布拉各衍射效率。此外,有望通过不均匀静磁场来控制衍射光的发散。 相似文献
10.
Effects of the resonant Bragg scattering of magnetostatic backward volume waves on the periodic structure of a conductive
meander pattern with an alternating current are analyzed theoretically and compared with experiment. It is shown that unlike
a static grating, a dynamic grating causes a frequency shift of the scattered wave. It is proposed that this phenomenon be
utilized for effective control of the intermodal conversion of magnetostatic waves.
Zh. Tekh. Fiz. 68, 105–112 (May 1998) 相似文献
11.
The features of spin wave emission from a ferromagnetic film in the direction of the propagation of a surface magnetostatic wave have been experimentally investigated at various input signal powers. Radiation in the form of two noise-like spin wave packets has been detected near the frequency corresponding to half the pump frequency. This radiation is caused by three-magnon processes of the decay of a surface magnetostatic wave and by the kinetic instability of spin waves. 相似文献
12.
给出了任意倾斜偏置磁场作用下相位失配时微波静磁波与导波光的磁光耦合方程,分析了相位失配对导波光衍射效率及其衍射方向的影响.计算了YIG薄膜波导中静磁反向体波与导波光非共线作用的Bragg衍射效率, 传统磁化时计算结果与实验结果一致.计算表明,与传统磁化情形相比,适当的偏斜磁场可使导波光衍射效率提高6dB以上;当导波光入射角保持不变时,由磁场方向改变引起的相位失配对衍射效率的影响不大.因此,优化偏置磁场方向是改善磁光Bragg器件衍射性能、提高磁光带宽的有效方法.
关键词:
磁光效应
Bragg衍射
静磁波 相似文献
13.
The influence of surface-layer vortex pinning in a type-II superconductor on the propagation of surface magnetostatic waves
in a ferromagnet-superconductor structure is analyzed. The pinning is assumed to be strong enough to prevent vortex displacement
under the influence of the Lorentz force generated by the surface magnetostatic waves, so that the ground state of the superconductor
is determined by the elastic properties of the vortex lattice and by pinning. In the given model the problem reduces to the
analysis of the wave spectrum in the scattered field created by the disordered vortex surface layer. A calculation shows that
the influence of this field on the surface magnetostatic-wave spectrum is slight and, hence, degradation of the shielding
properties of the superconductor does not take place in the presence of strong vortex pinning (as opposed to the ferromagnet-ideal
superconductor structure).
Fiz. Tverd. Tela (St. Petersburg) 40, 32–35 (January 1998) 相似文献
14.
15.
M. M. Shabat 《International Journal of Infrared and Millimeter Waves》1994,15(10):1651-1662
The general propagation characteristics of magnetostatic surface waves guided by a single interface of a semi-infinite nonlinear dielectric cover and a ferromagnetic substrate (YIG) have been derived. The nonlinear dielectric cover has intensity dependent refractive indices. The magnetostatic approximation is considered and retardation is ignored in describing the electromagnetic fields in the structure. The used magnetostatic approximation is leading to new waves and might be called nonlinear magnetostatic surface waves. The propagation of these waves is non-reciprocal in contrast to the linear magnetostaic surface waves, which had been only found in the negative direction of propagation. 相似文献
16.
A. V. Vashkovskii É. G. Lokk V. I. Shcheglov 《Journal of Experimental and Theoretical Physics》1998,87(4):776-787
The propagation of zero-exchange spin waves (magnetostatic waves) is investigated in yttrium iron garnet films having a regular
stripe domain structure with almost in-plane orientation of the domain magnetization vectors. The characteristics of the waves
are studied for magnetizations of the film parallel and perpendicular to projections of the [111] crystallographic axes onto
the plane of the film. It is established, in contrast with films having the domain magnetization vectors oriented close to
the normal to the plane of the film, that both the propagation of magnetostatic waves and the variation of the parameters
of the domain structure exhibit a distinctly pronounced hysteretic character as the magnetizing field is varied. The hysteresis
of the amplitude-frequency response, equiphase, and dispersion curves of the magnetostatic waves is investigated. The authors
examine how the hysteresis of these parameters is related to the hysteresis of the domain structure. The spectrum of magnetostatic
waves is found to have an interval of wavelengths (wave numbers) that are not excited in the unsaturated film when the applied
field is close to the saturation value, and this phenomenon as well exhibits hysteresis.
Zh. éksp. Teor. Fiz. 114, 1430–1450 (October 1998) 相似文献
17.
The universal magneto-optic (MO) coupled-mode equations for magnetostatic waves (MSWs) and guided optical waves (GOWs) under arbitrarily tilted bias magnetic fields are presented for the first time and, as an example, applied to the noncollinear Stokes interaction between the incident TE0-mode light and magnetostatic backward volume wave (MSBVW) excited by single-element microstrip line transducer in yttrium–iron–garnet (YIG) film. Our calculation indicates that, for the case of magnetization parallel to the MSBVW propagation direction, the diffraction efficiency (DE) is equal to the mode-conversion efficiency of the diffracted lights (MCDE) and the calculated curve of relative DE for the MSBVW-based MO Bragg cell in pure YIG waveguide is in good agreement with the experimental data. In contrast, the diffraction performance can be greatly improved by optimizing the bias magnetic field and the DE gain can be increased by 6.3 dB in the tangentially magnetized film. The angular dependences of the DE and the corresponding Bragg angle upon the magnetization direction are also discussed in the paper. 相似文献
18.
Kalluri D.K. Goteti V.R. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(5):797-801
The interaction of a circularly polarized electromagnetic wave with a switched-on magnetoplasma medium is considered. A static magnetic field in the direction of propagation is assumed to be present, resulting in longitudinal propagation. The incident wave splits into three waves whose frequencies are different from that of the incident wave. It is shown that these waves ultimately damp out if the plasma is even slightly lossy. The damping of the waves is interpreted in terms of their attenuation with distance and decay with time as they propagate in the lossy plasma. The attenuation-length and decay-time constants of the waves are obtained, and their dependence on the incident-wave frequency and the gyrofrequency is examined. Optimum parameters for an experiment to detect these waves are suggested 相似文献
19.
In this work, the dynamics and internal structure of shock waves in picosecond laser–material interaction are explored at
the atomistic level. The pressure of the shock wave, its propagation, and interaction zone thickness between the plume and
ambience are evaluated to study the effect of the laser absorption depth, ambient pressure, and laser fluence. Sound agreement
is observed between the MD simulation and theoretical prediction of shock wave propagation and mass velocity. Due to the strong
constraint from the compressed ambient gas, it is observed that the ablated plume could stop moving forward and mix with the
ambient gas, or move backward to the target surface, leading to surface redeposition. Under smaller laser absorption depth,
lower ambient pressure, or higher laser fluence, the shock wave will propagate faster and have a thicker interaction zone
between the target and ambient gas. 相似文献
20.
Zhan Fu Haixin Zhou Keqian Zhang 《International Journal of Infrared and Millimeter Waves》2003,24(2):239-252
Plane wave propagation in chiral plasma and chiral ferrite media is studied in kDB coordinate system. General wave equations and characteristic equations of plane waves propagating along an arbitrary direction in chiral plasma and in chiral ferrites are derived in simple formulations respectively. Four wavenumbers and their corresponding dispersion characteristics are resulted for propagation both along and normal to the biasing magnetic field. When plane wave with negative helicity propagates along the biasing magnetic field in chiral ferrites, backward waves emerge. However backward waves occur with both positive and negative helicities when propagating along the biasing magnetic field in chiral plasma. 相似文献