共查询到19条相似文献,搜索用时 78 毫秒
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提出了一种采用二元π位相板与柱面透镜组合而构成表面光波导型原子(或分子)分束器及其Mach-Zehnder干涉仪与X-分束器列阵的新方案,介绍了本方案的物理思想与基本原理,导出了光强分布、强度梯度、分束距离和分束路径的宽度与光学系统参数间的解析关系,并分析和讨论了本方案的潜在应用及其可行性. 研究表明,本方案设计新颖、光路简单,便于与其他元件组合构成具有表面微结构的集成原子(或分子)光学元器件及其全光型原子(或分子)芯片.
关键词:
原子(或分子)光波导
原子(或分子)分束器
原子(或分子)芯片
二元π位相板 相似文献
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高斯光束经过负球差透镜的聚焦 总被引:2,自引:0,他引:2
本文讨论高斯光束经过负球差透镜的聚焦,得到了聚焦光场轴上点的光强分布的表示式,并对其进行数值计算。数值计算结果表明,在负球差的情况下,得到光强的最大点位置(最佳聚焦点)相对于无球差情况,往透镜方向移动,并且,最佳聚焦点的光强较无球差时大,当Nw=1,Na=5,kS1=-0.2时,得到的最佳聚焦点的光强是无球差时的1.34倍。本文还讨论了透镜的菲涅尔数对聚焦光场分布的影响。结果表明,当透镜的菲涅尔数小于1时,球差对高斯光束的聚焦的影响可以忽略。 相似文献
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利用平板波导法研究了不同入射角度下周期排列开口谐振环负磁导率材料、周期排列金属杆负介电常数材料以及左手材料微波反射特性,并利用劈尖法研究了左手材料的负折射特性.实验结果表明:负磁导率材料反射率曲线形成反射峰,其对应的反射峰频率与材料的谐振频率一致;负介电常数材料反射率接近0dB;左手材料出现单个反射较小的反射峰,其峰值反射率随入射角度的增大而变大,即反射能力增强,且反射峰与透射峰有相对频移.劈尖法测量还表明,左手材料在9800MHz频率附近出现负折射现象,其折射率n为-0.796.
关键词:
左手材料
反射
负折射率 相似文献
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The characteristics of an imaging system formed by a left-handed material (LHM) slab of finite length are studied, and the influence of the finite length of the slab on the image quality is analyzed. Unusual phenomena such as surface bright spots and negative energy stream at the image side are observed and explained as the cavity effects of surface plasmons excited by the evanescent components of the incident field. For a thin LHM slab, the cavity effects are found rather sensitive to the length of the slab; the bright spots on the bottom surface of the slab may stretch to the image plane and degrade the image quality. 相似文献
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LIN Zhen MA Xue-ying LIANG Chang-hong ZENG Hao 《核聚变与等离子体物理》2007,27(3):256-259
Finite-difference time-domain (FDTD) method is used to simulate the propagation of electromagnetic wave in left-handed material slab (LHMs) with cold plasma model The effects of optical propagation in the left-handed material compared to convex lens are discussed. The wider the LHMs is, the stronger electric field of focusing image in left-handed material slab is confirmed by the simulation with various slab length. However, the outer image point location would slightly moves to the LHMs side when the length of LHMs is reduced. 相似文献
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A. K. Rastogi S. Mishra A. K. Tiwari 《International Journal of Infrared and Millimeter Waves》1995,16(3):601-614
Dispersion characteristics and wave impedance for the even and odd modes of the broad side coupled dielectric image guides are computed by using mode matching techniques. Dispersion curves for broadside image guide are plotted for various dielectric materials and dimensional parameters as a function of frequency. Normalized electric field for dominant electric field component E of TM even and odd modes for various half spacings between two dielectric slabs of broadside coupled image guide have been plotted. Polysterene ( r=2.56) and Stycast ( r=3.4) have been used as dielectric materials in fabricating broadside coupled image guide. This broadside coupled dielectric guide is very convenient as compared to the other dielectric guides. Since in case of broadside coupled image guide the dielectric slab can be bonded to the side metallic walls using some low loss adhesive material, while in other coupled dielectric guides the dielectric slab have to be supported by some low dielectric constant material (Eccofoam with r=1.02) to maintain the proper distance of side metallic walls from the dielectric slab. Since this structure is symmetrical, this configuration can be analysed in terms of even and odd mode phase velocities. The difference in these even and off mode phase velocities can be used to determine the coupling between coupled dielectric slab. Various couplers in this configuration can be realised. 相似文献
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A metamaterial slab, used as a superlens in a subwavelength imaging system, is frequently assumed homogeneous. It is the bulk
properties of the metamaterial which are responsible for the resolution of the transferred information in the image domain,
as a result of high transverse wave-vector coupling. However, how in a discretized metamaterial, individual meta-atoms (i.e.,
the meta-elements composing a negative index metamaterial slab) contribute to the imaging process is still actively studied.
The main aim of this paper is to investigate the consequences of using only a few meta-atoms as a negative index slab-equivalent
for subwavelength scale imaging. We make a specific choice for a meta-atom and investigate its resonant scattering patterns.
We report on how knowledge of these 3D scattering patterns provides a means to understand the transfer of high spatial frequencies
and assist with the design an improved negative index slab. 相似文献
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Negative refraction makes a perfect lens 总被引:7,自引:0,他引:7
Pendry JB 《Physical review letters》2000,85(18):3966-3969
With a conventional lens sharpness of the image is always limited by the wavelength of light. An unconventional alternative to a lens, a slab of negative refractive index material, has the power to focus all Fourier components of a 2D image, even those that do not propagate in a radiative manner. Such "superlenses" can be realized in the microwave band with current technology. Our simulations show that a version of the lens operating at the frequency of visible light can be realized in the form of a thin slab of silver. This optical version resolves objects only a few nanometers across. 相似文献
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We report the imaging properties of a two-dimensional rectangular-lattice photonic crystal (PC) slab consisting of rectangular metallic rods immersed in a dielectric background. By simulating the electromagnetic wave propagation through such a PC slab with the finite-difference time-domain method, we find that a point source placed in the vicinity of the PC slab can form a good-quality image through the slab. The frequency region where a good-quality image is formed can be controlled by choosing the direction along which the PC slab surface normal is placed. 相似文献