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1.
We report the coexistence of TE and TM surface modes in certain same
frequency domain at the interface between one isotropic regular medium and
another biaxially anistotropic left-handed medium. The conditions for the
existence of TE and TM polarized surface waves in biaxially anisotropic
left-handed materials are identified, respectively. The Poynting vector and
the energy density associated with surface modes are calculated.
Depending on the system parameters, either TE or TM surface modes can
have the
time averaged Poynting vector directed to or opposite to the mode phase
velocity. It is seen that the characteristics of surface waves in biaxially
anisotropic left-handed media are significantly different from that in
isotropic left-handed media. 相似文献
2.
The coexistence of TE-TM surface waves in uniaxially anisotropic left-handed materials 总被引:1,自引:0,他引:1
We investigate theoretically the characteristics of surface waves in uniaxially anisotropic left-handed materials. The constraints for the existence of TE and TM polarized surface waves in uniaxially anisotropic left-handed materials are identified. We discuss mainly whether TE and TM polarized surface modes may coexist in the same frequency domain at the interface between one isotropic regular medium and another uniaxially anisotropic left-handed medium. It is shown that the answer to the coexistence of TE and TM surface modes is really positive. The Poynting vector and the density of energy associated with surface modes are calculated. Depending on the system parameters either TE or TM surface modes has the time averaged Poynting vector directed opposite or same to the mode phase velocity. In the presence of anisotropy, negative refraction does not need to be left-handed. We show that the characteristics of surface waves in uniaxially anisotropic left-handed media are significantly different from that in isotropic left-handed media. 相似文献
3.
In this paper, we investigate the electromagnetic surface waves localized at the interface of the homogeneous dielectric medium and a semi-infinite one-dimensional photonic crystal (1D PC), theoretically. The semi-infinite 1D PC is made of alternative layers of left-handed (LH) and right-handed (RH) materials in the presence of a thin nonlinear cap layer. We consider magnetic permeability and electric permittivity of LH layers being dispersive and non-dispersive. We used an analytical direct matching procedure within the Kronig-Penny model to analyze the dispersion behavior of surface waves with controllable localization. It is shown that the thin nonlinear cap layer acts as a tool to change the backward surface waves to forward ones and vice versa and it plays an important role on the localization of them. Also we show that when the LH layers are chosen dispersive, negative dispersion of surface waves are obtained in a wide range of radiation angle and frequency, and we propose an approach to calculate the applied electric field intensity that leads to switching of surface waves from backward to forward and creating a surface mode with maximum localization. 相似文献
4.
左手系材料界面上的非线性TE电磁波 总被引:4,自引:4,他引:0
针对电磁波在非线性左手系材料中的传播性质, 分别研究了左、右手系材料界面以及两左手系材料界面上非线性TE表面波的传播行为讨论了导波的频率特性、色散关系以及群速度随频率的变化规律分析表明,两种界面上的非线性TE表面波均存在频率通带和禁带,且带宽是传播功率的函数揭示了在一定条件下,左、右手系材料界面上既可以支持正向传播的非线性TE表面波,也可以支持反向传播的非线性TE表面波;两左手系材料界面上表面波的传播性质因材料参量的变化差异较大,一定参量条件下,该界面上仅支持反向传播的非线性TE表面波. 相似文献
5.
Expressions for effective parameters are derived for a medium composed of alternating layers of a uniaxial ferromagnet and
a semiconductor. The medium under investigation is a biaxial bigyrotropic crystal. In the case of a transverse magnetooptical
configuration, bulk and surface waves at the vacuum-periodic structure interface are considered. Numerical analysis of dispersion
relations for intrinsic TE and TM modes controlled in different frequency ranges is carried out. 相似文献
6.
Tingting Tang 《Optik》2013,124(24):6509-6511
We propose a polarization splitter (PS) based on the slow light effect in a three-layer waveguide that consists of left-handed material (LHM) and dielectric layers with no birefringence. Transverse electric (TE) and transverse magnetic (TM) waves can be split by the intrinsic configuration of permittivity and permeability of LHM and dielectric layers. Simulation results are given to discuss the influence of electromagnetic parameters on the properties of our PS, and the capture and release of TE or TM waves are also realized in our PS which provides a flexible method to modulate the switching of different polarization waves. 相似文献
7.
We propose a type of photonic heterostructure by combining dielectric one-dimensional (1D) defective photonic crystals (PCs)
and magnetic 1D defective PCs. Both of the two PCs consist of alternating positive-index-material (PIM) layers with a negative-index-material
(NIM) defect layer. It is demonstrated by transfer matrix method that there is a polarization- and direction-independent defect
mode in a wide incident-angle range within Bragg gaps in the heterostructure. The field distributions prove that the dielectric
1D defective PC benefits to achieve the approximately omnidirectional defect mode for TE waves while the magnetic 1D defective
PC benefits for TM waves. Such a structure is useful for designing polarization-independent and omnidirectional or large incident
angle narrow-passband filters in optical devices. 相似文献
8.
We study the transmission properties in the one-dimensional
photonic crystal containing alternate anisotropic left-handed
material (LHM) layers and regular isotropic right-handed material
(RHM) layers. For such an anisotropic case, the dispersion
relation from the Bloch theorem is derived and the Bragg gaps of
the periodic structure are observed. It is found that in the m=0
Bragg gap, there is an omnidirectionally reflectional (ODR)
region, which is also invariant with a change of scale length,
similar with the
[`(n)]=0\bar{n}=0
gap in isotropic one-dimensional
photonic crystal. With the aid of effective medium theory (EMT),
the analytic expressions of all six elements of the effective
electric permittivity tensor and magnetic permeability tensor are
obtained. By using these results, we investigate the ODR region in
the m=0 Bragg gap in all the possible cases of both TE and TM
modes. We find that with different choices of parameters, the
m=0 Bragg gap has different transmission properties, and the ODR
region in it changes, consequently. The edges of the ODR region
are given out in these cases. To one's interest, these results
predict a complete reflection region in the m=0 Bragg gap, which
is able to omnidirectionally reflect waves in both TE and TM modes. 相似文献
9.
We theoretically study the transport of electronic waves through a graphene sheet applied by a random voltage pattern in which the magnitudes and/or the widths of the voltages are random. When the magnitudes of the voltages exceed the electronic energy, the applied region can be considered as left-handed (LH) layers. Compared to the disordered structures with right-handed (RH) layers only, the spectra of the (average) density of states and the localization lengths in mixed random structures with RH and LH layers all show the suppression of Anderson localization, owing to the phase compensation effect of LH layers that reduces the long-range interference in the random system. 相似文献
10.
The TE/TM polarization conversion characteristics of dielectric grating composed of left-handed materials for the case of
plane wave oblique incidence are carefully investigated by a method which combines the multimode network theory with the rigorous
mode matching method. It is indicated that complete polarization conversion between TE and TM modes can be realized using
left-handed gratings. This can hardly achieve in the conventional right-handed gratings. Comparisons of polarization conversion
properties between right-handed gratings and left-handed gratings are given with physical explanations. This unique merit
of left-handed periodic structure is of important significance for accurate design of new millimeter wave TE/TM polarization
converters. 相似文献
11.
12.
13.
Surface waves that propagate along the interface between an isotropic linear or nonlinear (of the Kerr type) dielectric and a topological insulator have been studied theoretically. A dispersion relation for surface waves, which are represented by superpositions of TE and TM waves, has been obtained. This hybridization occurs because, upon passage through the interface, the polarization of a surface wave changes, which is caused by an induced surface current (which is transverse to the electric field vector of the wave). The surface current of this kind is characteristic of topological insulators. Expressions for the energy flux transferred by a surface wave have been given. 相似文献
14.
Band structures of one-dimensional(1D)photonic crystals(PCs)containing dispersive left-handed metamaterials are studied theoretically.The results show that the structure possesses a type of photonic band gap originating from total internal reflection(TIR).In contrast to photonic band gaps corresponding to zero average refractive index and zero phase.the TIR gap exhibits sharp angular effect and has no polarization effect.It should also be noted that band structures of transverse electric(TE) and transverse magnetic(TM) mode waves are exactly the same in the PCs we studied. 相似文献
15.
Yenny Pinto Julien Sarrazin Anne-Claire Lepage Xavier Begaud Nicolas Capet 《Applied Physics A: Materials Science & Processing》2014,117(2):693-697
This paper presents a lightweight microwave absorber suitable for space applications. The absorber is based on a resistive high-impedance surface (RHIS) optimized to achieve reflection under ?15 dB in the band (2–2.3 GHz) at oblique incidence for transverse electric (TE) and transverse magnetic (TM) polarizations. A first classical isotropic RHIS structure is shown to be limited to angles of incidence up to 40° for TE polarized waves and up to 35° for TM polarized waves. So the objective of this contribution is to present a second solution based on an anisotropic RHIS structure which presents good absorption of incident waves in TE and TM polarizations for larger angles of incidence. An example is presented for an incidence angle of 65°. 相似文献
16.
填充率渐变型波状结构二维光子晶体 总被引:6,自引:2,他引:4
填充率渐变引起的能带结构和等频面结构的变化是填充率渐变型波状结构二维(2D)光子晶体(PC)产生光路转弯现象的根本原因,由于TM模和TE模在能带结构上存在差异,光路转弯现象就具有明显的偏振选择特性,能够实现归一化频率a/λ为0.29~0.33的偏振分束。利用时域有限差分(FDTD)法模拟了TM模的U型转弯波导,发现出射光位置对入射波长和入射角的变化很敏感,位移变化量分别达到0.38μm/10 nm和0.29μm/(°)。利用TM模的U型转弯波导构建了新型的平行平面谐振腔,并指出由填充率渐变型波状结构二维光子晶体和一维多层薄膜构成的混合结构在光分束和抑制光束发散方面的作用及其在平行平面谐振腔中的潜在应用。 相似文献
17.
Shao-Wei Wang Wei Lu Xiao-Shuang Chen Mei Zhou Xue-Chu Shen 《International Journal of Infrared and Millimeter Waves》2003,24(6):963-971
Photonic band gap (PBG) in two-dimensional (2D) anisotropic photonic crystal (PC) constructed of rectangular bars has been numerically studied by using Transfer Matrix Method (TMM). The results show that the PBG is bounded by the lower band edge of TE wave and the upper band edge of TM wave. Its width simply increases with increasing of shape parameter . It reaches a maximum value as the structure degenerates into its 1D counterpart, due to the complete overlapping of gaps in TE and TM waves. The anisotropy in PC structure results in the transmission anisotropic property. One can design the PBG structures in different incident directions to match their application demand. 相似文献
18.
The propagation of surface waves along the interface between a ferrodielectric and a material that represents an array of amorphous ferromagnetic microwires has been studied. The dispersion characteristic of a magnetically controlled TE wave has been obtained, and frequency intervals have been found in which surface or localized, partially localized, and volume waves may exist. It has been shown that a TM wave in the given structure cannot be a surface wave. 相似文献
19.
Meng Huang Shanjia Xu Ke Wu 《International Journal of Infrared and Millimeter Waves》2006,27(9):1293-1306
The scattering and radiation characteristics of a step discontinuity in left-handed (LH) slab waveguide operating in evanescent
surface mode of TE and TM polarization are analyzed by a method, which combines the rigorous mode-matching method with the
multi-mode network theory. In the analysis the radiation problem is transformed into a propagation problem so as to tremendously
simplify the calculation procedure. The dispersion properties of the grounded planar LH slab waveguide for both ordinary and
evanescent surface modes are examined, from which the left-hand property of the operating mode is testified. The relative
scattered power and radiation pattern of the step are given for the first time, from which the backward radiation of the stepped
LH guide is clearly demonstrated. The frequency scanning characteristics of the step under consideration in this paper are
just opposite to that of the ordinary antenna, which makes the considered structure promising candidate for new type of planar
antennas.
Supported by the National Natural Science Foundation of China (No.60371010, No.60471037, No. 63531020) 相似文献
20.
Prabhakaran Letha Premlal Dinesh Chandra Tiwari Vandana Chaturvedi 《The European Physical Journal B - Condensed Matter and Complex Systems》2018,91(5):78
We present a detailed theoretical analysis about the influence of surface polaritons on the transmission properties of electromagnetic waves at the periodically corrugated interface between the vacuum and left-handed material by using nonlinear boundary condition approach. The principle behind this approach is to match the wave fields across the grating interface by using a set of linear wave equation with nonlinear boundary conditions. The resonant transmission of the incident electromagnetic radiation in this structure is feasible within a certain frequency band, where there is a range of frequency over which both the electric permittivity and the magnetic permeability are simultaneously negative. The enhanced transmission is attributed to the coupling of the incident electromagnetic wave with the excited surface polaritons on grating interface. Finally, we present the numerical results illustrating the effect of the structural parameters and angle of incidence on the transmission spectra of a TM polarized electromagnetic wave. 相似文献