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931.
932.
分析了单轴各向异性左手介质表面的Goos-H?nchen位移,分别给出了光轴与两种介质的界面垂直和平行情形下的Goos-H?nchen位移解析表达式,并分析了Goos-H?nchen位移产生的条件以及位移的正负情况.还采用菲涅尔近似的方法给出了临界角附近的Goos-H?nchen位移表达式,结果表明临界角附近的Goos-H?nchen位移是入射光的束腰半径和入射角的函数,并且给出了临界角入射时Goos-H?nchen位移的较为简洁的近似表达式,这样就在整个角度的取值范围内都给出了Goos-H?nchen位移的表达式.
关键词:
Goos-H?nchen位移
左手介质
单轴各向异性
临界角 相似文献
933.
A novel design method for high Q piezoelectric resonators was presented and proposed using the 3-D equations of linear piezoelectricity with quasi-electrostatic
approximation which include losses attributed to mechanical damping in solid and resistance in current conduction. There is
currently no finite element sofware for estimating the Q of a resonator without apriori assumptions of the resonator impedance or damping. There is a necessity for better and more
realistic modeling of resonators and filters due to miniaturization and the rapid advances in frequency ranges in telecommunication.
We presented new three-dimensional finite element models of quartz and barium titanate resonators with mechanical damping
and resistance in current conduction. Lee, Liu and Ballato’s 3-D equations of linear piezoelectricity with quasi-electrostatic
approximation which include losses attributed to mechanical damping in solid and resistance in current conduction were formulated
in a weak form and implemented in COMSOL. The resulting finite element model could predict the Q and other electrical parameters for any piezoelectric resonator without apriori assumptions of damping or resistance. Forced
and free vibration analyses were performed and the results for the Q and other electrical parameters were obtained. Comparisons of the Q and other electrical parameters obtained from the free vibration analysis with their corresponding values from the forced
vibration analysis were found to be in excellent agreement. Hence, the frequency spectra obtained from the free vibration
analysis could be used for designing high Q resonators. Results for quartz thickness shear AT-cut and SC-cut resonators and thickness stretch poled barium titanate resonators
were presented. An unexpected benefit of the model was the prediction of resonator Q with energy losses via the mounting supports. 相似文献
934.
P. Billaud J.-R. Huntzinger E. Cottancin J. Lermé M. Pellarin L. Arnaud M. Broyer N. Del Fatti F. Vallée 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,43(1-3):271-274
The extinction spectrum of single silver nanoparticles
with size ranging from 20 to 80 nm is investigated with the spatial
modulation spectroscopy technique using either a tunable laser or a white
lamp as the broadband source. Results are in good agreement with the
prediction of the Mie theory, permitting to extract the nanoparticle size
from the measured absolute value of the optical extinction cross-section. In
contrast, the deduced refractive index of the nanoparticle environment and
the reduction of the electron mean free path show a large dependence on the
precise value of the bulk silver dielectric function. 相似文献
935.
L. Gao X. P. Yu 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,55(4):403-409
We derive expressions for the effective nonlinear susceptibility
tensors for both the second harmonic generation (SHG) and induced
third harmonic generation (THG) of nonlinear composite materials,
in which nondilute coated particles with radial dielectric
anisotropy are randomly embedded in the linear host. Two types of
coated particles are considered. The first is that the core
possesses a second order nonlinear susceptibility and the shell is
linear and radially anisotropic, while the second is that the
core is linear with radial anisotropy and the shell has a second
order nonlinear susceptibility. We observe greatly enhanced SHG
and THG susceptibilities at several surface plasmon resonant
frequencies. For the second model, due to the coating material
being metallic, there exists two fundamental resonant frequencies
ωc1 and ωc2, whose difference
ωc2-ωc1 is strongly dependent on the interfacial
parameter and the radial dielectric anisotropy. Furthermore, in
both systems, the adjustment of the dielectric anisotropy results
in larger enhancement of both SHG and induced THG susceptibilities
at surface plasmon resonant frequencies than the corresponding
isotropic systems. Therefore, both the core-shell structure and
the dielectric anisotropy play important roles in determining the
nonlinear enhancement and the surface resonant frequencies. 相似文献
936.
晶粒间界相对纳米Nd_2Fe_(14)B各向异性和矫顽力的影响 总被引:1,自引:0,他引:1
本文采用立方晶粒结构模型研究了晶粒间界相对纳米硬磁材料各向异性和矫顽力的影响.结果表明:晶粒间界相减弱了交换耦合作用.当晶粒尺寸D为定值时,随着晶粒间界相厚度d的增加,晶粒平均各向异性单调增加,而材料的有效各向异性Keff、矫顽力单调减小.我们计算的矫顽力随晶粒尺寸的变化与相关理论和实验结果基本一致. 相似文献
937.
In this paper, a new channel drop filter in two dimensional photonic crystals with mirror cavities is proposed. In the structure,
three cavities are used. One is used for a resonant tunneling-based channel drop filter. The others are used to realize reflection
feedback in the bus waveguide, which consists of a point defect micro-cavity side-coupled to a waveguide. The simulation results
by using the finite-difference time-domain method conclude 98% output efficiency. 相似文献
938.
939.
940.
LUO En & LI WeiHua Department of Applied Mechanics Engineering Sun Yat-sen University Guangzhou China 《中国科学G辑(英文版)》2007,50(3):370-378
According to the basic idea of classical yin-yang complementarity and modern dual-complementarity, in a simple and unified way proposed by Luo, some basic principles in the dynamic theory of viscoelastic materials with voids can be estab- lished systematically. In this paper, an important integral relation in terms of con- volutions is given, which can be considered as the generalized principle of virtual work in mechanics. Based on this relation, it is possible not only to obtain the principle of virtual work and the reciprocal theorem, but also to derive systemati- cally the complementary functionals for the eight-field, six-field, four-field simpli- fied Gurtin-type variational principles and the potential energy-functional for the two-field one in the dynamic theory of viscoelastic materials with voids by the generalized Legendre transformations given in this paper. Furthermore, with this approach, the intrinsic relationship among various principles can be explained clearly. 相似文献