共查询到20条相似文献,搜索用时 31 毫秒
1.
J. W. Menezes L. F. Avila E. S. Braga L. Cescato 《Applied Physics A: Materials Science & Processing》2011,103(3):631-634
In this paper we compare the sensitivity of the Extraordinary Transmittance (ET) peak position with the surrounding media
for two types of metallic structures: arrays of holes and arrays of slits recorded in Au films. Both types of array were fabricated
using Interference Lithography (IL) with a period of 700 nm and an Au thickness of 150 nm. The transmission spectra measurements
were performed at normal incidence using a spectrophotometer. The results show that an array of slits presents a higher sensitivity
for the surrounding media than the array of holes. Theoretical TE and TM simulations of the transmission spectra for the slit
arrays agree very well with the experimental results, confirming the better sensitivity of the slit arrays. 相似文献
2.
Y. Ben-Aryeh 《Applied physics. B, Lasers and optics》2008,91(1):157-165
The convolution between spatial modes of two different parts of an optical system can convert evanescent waves into propagating
waves. This principle is applied to different optical systems for analyzing various effects in transmission enhancements experiments.
We discuss here the differences between the present principle which is related to broadening of resonances and the near-field
optical microscopy based on a tunneling effect by a tip detector. The present analysis is applied in particular to two systems:
a) transmission enhancement in one slit by coupling the transmitted radiation with transversal Fabry–Pérot electromagnetic
(EM) modes, and b) transmission enhancement by coupling between a metallic film with arrays of holes and surface plasmons
(SP). The present approach gives more information on transmission enhancement phenomena than that obtained by conventional
treatments and can also solve certain disagreements between different theories. The differences between the present process
of converting evanescent waves into propagating waves, and that related to the new development of getting a super-resolution
by an hyperlens are discussed.
PACS 41.20.Jb; 73.20.Mf; 42.79.Dj 相似文献
3.
J.?Kindler P.?Banzer S.?Quabis U.?Peschel G.?Leuchs 《Applied physics. B, Lasers and optics》2007,89(4):517-520
We investigate the transmission of focused beams through single subwavelength holes in a silver film. We use radially and
azimuthally polarized light to excite higher-order waveguide modes as well as to match the radial symmetry of the aperture
geometry. Remarkably, the transmission properties can be described by a classical waveguide model even for thicknesses of
the silver film as thin as a quarter of a wavelength.
PACS 42.25.Bs; 42.25.Ja; 42.79.Gn 相似文献
4.
A.V. Lavrinenko A. Têtu L.H. Frandsen J. Fage-Pedersen P.I. Borel 《Applied physics. B, Lasers and optics》2007,87(1):53-56
We present results on broadband transmission through photonic crystal waveguide bends optimized for slow-light modes. Theoretical
analysis and topology optimization are complemented by experimental verification of designs fabricated in SOI material.
PACS 42.82.Et; 42.79.Gn; 42.70.Qs 相似文献
5.
Experimental studies of extraordinary light transmission through periodic arrays of subwavelength square and rectangular holes in metal films
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We fabricate a series of periodic arrays of subwavelength
square and rectangular air holes on gold films, and measure the
transmission spectra of these metallic nanostructures. By changing
some geometrical and physical parameters, such as array period, air
hole size and shape, and the incident light polarization, we verify
that both global surface plasmon resonance and localized waveguide
mode resonance are influential on enhancing the transmission of
light through nanostructured metal films. These two resonances
induce different behaviours of transmission peak shift. The
transmission through the rectangular air-hole structures exhibits an
obvious polarization effect dependent on the morphology. Numerical
simulations are also made by a plane-wave transfer-matrix method and
in good consistency with the experimental results. 相似文献
6.
The ultrasonic transmission through plates perforated with 2 × 2 or 3 × 3 square array of subwavelength holes per unit cell are studied by numerical simulations. Calculations are obtained by means of a theoretical model under the rigid-solid assumption. It is demonstrated that when the inter-hole distance within the unit cell is reduced, new transmission dips appear resulting from Wood anomalies that have influence on the second and the third order Fabry-Perot peak. When the inter-hole distance within the unit cell is reduced, the transmission spectrum of the multiple-sublattice holes arrays tends to the transmission spectrum of a plate perforated with only one hole in the unit cell. 相似文献
7.
We fabricated a specially designed polymer long-periodwaveguide grating to demonstrate the phenomenon of dual resonance arising from light coupling between the core mode and a low-ordercladding mode of the waveguide. By varying the temperature of the grating, we observed the onset and the evolution of the dual-resonancewavelengths. The separation between the dual-resonancewavelengths was varied by ∼110 nm with a temperature variation of ∼10 °C. The experimental results are explained well by the simulation results. PACS 42.79.Dj; 42.79.Gn 相似文献
8.
A space-variant optical transmission filter is demonstrated for which a simplified process is used to tailor the spatial response of the filter across the surface of a single wafer. A multilayer stack, of alternating high or low refractive index dielectric materials, was used to produce a narrow transmission notch in the center of a wide stop band. Subsequent patterning and etching of arrays of holes through the volume of the dielectric stack was performed to control the fill factor of the dielectric in the layers. The position of the transmission notch within the reflection spectrum was varied across the device surface by adjusting the hole diameter of the hole arrays. Experimental and numerical simulation were used to confirm the space-variant transmission characteristics of a single-wafer sample with two zones of different hole diameter arrays in the 1550 nm wavelength regime. 相似文献
9.
利用电子束直写系统和反应离子束刻蚀的方法制作了周期性排列H-形空气槽.样品的参量:金膜的厚度为120 nm,石英基底的厚度0.8 mm(其中有5 nm厚的铬层),样品是由30×30个单个H-形周期排列形成的,总体尺寸为40×40 μm2.每个H-形之间的周期为1.1 μm,H-形的臂长均为500 nm,空气槽的宽度为120 nm.然后用实验的方法测量了在近红外波段的透过曲线,在近红外波段1.6 μm处的透过率约为16.3%,用传输矩阵的方法对H-形空气槽结构进行了理论模拟,实验与理论模拟结果吻合较好.随后研究了当入射光的偏振方向与H-形结构的长轴之间的夹角分别为0°、30°、45°、60°和90°时透过曲线的变化情况.通过实验和理论表明,表面等离子体在这种特殊的结构中仍然存在,并且在光的增强透过起着决定性的作用. 相似文献
10.
Benisty H. Lalanne PH. Olivier S. Rattier M. Weisbuch C. Smith C.J.M. Krauss T.F. Jouanin C. Cassagne D. 《Optical and Quantum Electronics》2002,34(1-3):205-215
We address the issue of out-of-plane losses in two-dimensional (2D) photonic crystals (PC) etched through a GaAs monomode waveguide clad with standard GaAlAs alloys. We correlate experimental transmission of PCs with two kinds of loss simulation results. The first kind is 2D and introduces an ad hoc imaginary index in the air holes to account for the losses [see (Benisty et al. Appl. Phys. Lett. 76, 532, 2000)]. The second kind is a novel exact three-dimensional calculation inspired by grating-Fourier analysis that provides quantitatively unprecedented agreement with experimental measurements taking into account hole depth as a limiting parameter. We conclude that, in revision to the conclusions of the above reference, the experimental losses are not the intrinsic ones, being larger by a factor of 5 to 10 due to insufficient hole depth. The transition occurs at a critical etch depth shown to be here around 700 nm. We thus predict, for holes deeper than 700 nm, much improved crystals with very low transmission losses and microresonators with ultra-high quality factors. 相似文献
11.
Experimental study of transmission enhancement of evanescent waves through silver films assisted by surface plasmon excitation 总被引:1,自引:0,他引:1
N. Fang Z. Liu T.-J. Yen X. Zhang 《Applied Physics A: Materials Science & Processing》2005,80(6):1315-1325
In this paper, we investigated an essential precursor of superlensing: enhancing the transmission of evanescent waves assisted by excitation of surface plasmon. Using natural roughness as a well characterized grating, the transmission of evanescent waves is studied through silver thin films of increasing thickness. Measurements and calculations are performed in the wavelength range of 514.5 nm to 351.1 nm where the real part of the permittivity of silver is negative. Pronounced peaks due to surface-plasmon excitations are observed in the transmission spectra. We found the transmission of evanescent waves rapidly grows with the film thickness up to about 50 nm, after which it decays as loss becomes significant. As the permittivity of a silver slab approaches -1, we experimentally observed a broadening of surface plasmon bandwidth. Our study indicates a pathway to access the deep subwavelength features by metamaterial superlens. PACS 42.79-e; 42.30.Wb; 78.20.Ci; 78.66.Bz 相似文献
12.
Investigation of the guided-mode characteristics of hollow-core photonic band-gap fibre with interstitial holes
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This paper investigates the guided-mode characteristics of hollow-core photonic band-gap fibre (HC-PBGF) with interstitial holes fabricated by an improved twice stack-and-draw technique at visible wavelengths. Based on the simulation model with interstitial holes, the influence of glass interstitial apexes on photonic band-gaps is discussed. The existing forms of guided-mode in part band gaps are shown by using the full-vector plane-wave method. In the experiment, the observed transmission spectrum corresponds to the part band gaps obtained by simulation. The fundamental and second-order guided-modes with mixture of yellow and green light are observed through choosing appropriate fibre length and adjusting coupling device. The loss mechanism of guided-modes in HC-PBGF is also discussed. 相似文献
13.
金属薄膜上制备的表面等离激元颜色滤波器具有很强的颜色可调性. 在200 nm厚的金膜上, 通过聚焦离子束刻蚀, 制备一系列周期逐渐变化的圆形、方形、矩形亚波长尺寸小孔方阵列表面等离激元颜色滤波器, 改变入射光的偏振方向, 观察其超透射滤波现象. 研究发现: 对于矩形小孔阵列, 其透射光颜色随入射光偏振方向的变化而改变; 而对于圆形、方形的小孔阵列, 其透射光颜色对入射光的偏振方向并不敏感. 分析表明, 对于金膜上刻蚀的小孔结构, 虽然结构的周期性导致的表面等离激元极化子会对透射光的颜色变化产生一定影响, 但是随小孔形状变化的局域表面等离激元共振才是影响透射光颜色的决定性因素. 如果入射光没有在小孔中激发出局域表面等离激元, 则表面等离激元极化子对透射光的影响也会消失. 根据不同形状小孔周期结构透射光颜色随入射光的偏振变化特点, 制备出了包含两种小孔形状的复合周期结构. 随着入射光偏振方向的改变, 该结构会显示出不同的颜色图案.
关键词:
表面等离激元极化子
局域表面等离激元
颜色滤波器
亚波长小孔阵列 相似文献
14.
The metallic films perforated with a periodic array of air holes show extraordinary optical transmission properties. In this paper the influence of the incident light's polarization direction and the arrays’ period on the transmission through the rectangular hole arrays immersed in a metallic film is studied by utilizing the finite-difference time-domain method. The results show that the intensities and number of the transmission peaks can be adjusted by changing the incident light's polarization direction, while the intensities can keep constant for some particular frequencies. The transmission peak's wavelength can be easily controlled by altering the lattice period parallel to the electric field for the rectangular holes. These results maybe provide reference for the design of multiple-wavelength resonance devices. 相似文献
15.
设计了一种新型高双折射光子晶体光纤,即其包层引入椭圆形空气孔,且以三角晶格方式周期排列,纤芯引入亚波长尺寸(~0.16 μm)的微型双孔结构阵列.采用全矢量有限元法和各向异性完美匹配层边界条件分析了该型光子晶体光纤的双折射特性和色散特性,详细介绍了该光子晶体光纤在不同的椭圆率、椭圆归一化面积、微型双孔孔径、两小孔之间间距的情况下双折射和限制损耗随波长的变化曲线.模拟结果表明,通过同时在包层和纤芯引入非对称性,获得了较高的双折射(~10-3量级)和极低(~10-4 dB/km)的限制损耗.提供了一种新的光子晶体光纤设计方法,即通过同时在包层和纤芯引入新结构来同时获得高双折射和低损耗. 相似文献
16.
Bravo-Abad J Fernández-Domínguez AI García-Vidal FJ Martín-Moreno L 《Physical review letters》2007,99(20):203905
By using a theoretical formalism able to work in both real and k spaces, the physical origin of the phenomenon of extraordinary transmission of light through quasiperiodic arrays of holes is revealed. Long-range order present in a quasiperiodic array selects the wave vector(s) of the surface electromagnetic mode(s) that allows an efficient transmission of light through subwavelength holes. 相似文献
17.
He SK Zhang WJ Liu HF Xue GM Li BH Xiao H Wen ZC Han XF Zhao SP Gu CZ Qiu XG 《J Phys Condens Matter》2012,24(15):155702
We present results of transport measurements on superconducting Nb films with diluted triangular arrays (honeycomb and kagomé) of holes. The patterned films have large disk-shaped interstitial regions even when the edge-to-edge separations between nearest neighboring holes are comparable to the coherence length. Changes in the field interval of two consecutive minima in the field dependent resistance R(H) curves are observed. In the low field region, fine structures in the R(H) and T(c)(H) curves are identified in both arrays. Comparison of experimental data with calculation results reveals that these structures observed in honeycomb and kagomé hole arrays resemble those in wire networks with triangular and T(3) symmetries, respectively. The findings suggest that even in these specified periodic hole arrays with very large interstitial regions, the low field fine structures are determined by the connectivity of the nanostructures. 相似文献
18.
Superenhanced light transmission through subwavelength rectangular hole
arrays have been reported and some investigations have been made into the
physical origin of this phenomenon [K.J. Klein Koerkamp et al., Phys. Rev. Lett.
92, 183901 (2004)]. In our current work, by performing FDTD (finite
difference in the time domain) numerical simulations, we demonstrate that
mechanism that is different from surface plasmon polaritons set up by the
periodicity at the in-plane metal surfaces may account for this
superenhanced light transmission. We suggest that for arrays of rectangular
holes with small enough width in comparison to the wavelength of the
incident light, standing electromagnetic fields can be set up inside the
cavity by the surface plasmons on the hole walls with its intensity being
substantially enhanced inside the cavity. So resonant cavity-enhanced light
transmission is predominant and responsible for its superenhanced light
transmission. Rectangular holes behave as Fabry-Pérot resonance cavities
except that the frequency of their fundamental modes is restricted by their
TM cutoff frequency. However we believe that both localized surface plasmon
modes and surface plasmon polaritons set up by the periodicity at the
in-plane metal surfaces have their shares in extraordinary optical
transmission of rectangular hole arrays especially when the width of the
rectangular hole is not small enough and the metal film is not thick enough. 相似文献
19.
E. Bortchagovsky G. Colas des Francs D. Molenda A. Naber U.C. Fischer 《Applied physics. B, Lasers and optics》2006,84(1-2):49-53
We recently found that the intensity of the electric near field of a triangular aperture in a metal film is strongly localized
at one edge of the aperture for incident light polarized perpendicular to this edge. Previous numerical calculations of the
near field of a triangular aperture in a planar metal film, using the field susceptibility technique, yielded a nearly quantitative
agreement with the experiments. Using this numerical technique, we have investigated the influence of an obliquely incident
plane wave on the near field of small circular and triangular apertures. An interpretation of the numerical results leads
to a deeper understanding of the way in which light transmission through the aperture is excited. The data suggest that after
excitation of currents in the metal film by the incident light, a scattering of these currents by the aperture generates the
near field of the aperture. We found that the excitation of small apertures (size <100 nm) is due to a tangential magnetic
field whereas the perpendicular electric field plays no role. The excitation of a small aperture can thus be described exclusively
by a magnetic polarizability. We found that for thin metal films an interference of the scattered field with the field transmitted
through the metal film changes the near field pattern.
PACS 41.20.-q; 42.79.Ag; 68.37.Uv; 78.67.-n 相似文献
20.
J. Chang H. P. Wang K. Zhou B. Wei 《Applied Physics A: Materials Science & Processing》2012,107(1):139-143
In this report, we present experimental results of transmittance through nanohole arrays created onto Au films on glass substrates.
110-nm-thick Au films with arrays of nanoholes were fabricated by using self-assembled polystyrene spheres, of which the diameters
were reduced to designed values on site by dry etching, as a template. Transmission spectra of the nanostructured Au films
show strong enhancement (more than 45%) in a wide range from 300 nm to 1600 nm, the measurement wavelength range. Besides
a peak observed at around 500 nm in all spectra, a wider peak on the longer wavelength side was observed, which shifted to
longer wavelength when periodicities of the hole arrays were increased. 相似文献