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1.
《Superlattices and Microstructures》1994,15(4):459-462
Samples consisting of Ag fine particles 4nm in size placed near to an Al surface were prepared by depositing Ag-SiO2 composite films by a rf cosputtering method onto vacuum-evaporated Al films. Angle-scan attenuated total reflection (ATR) measurements were performed over a wide wavelength range (λ=350-630nm) covering the resonance region (λ-410nm) of localized surface plasmon (LSP) in the Ag particles. It was found that the existence of Ag fine particles near to the Al surface led to a deformation of the dispersion curve of the surface plasmon polariton (SPP) propagating on the Al surface, in particular, in the LSP resonance region. The interaction between LSP and SPP was found to become much stronger as the distance between the particles and the surface decreases. The theoretical calculations based on the effective medium theory, which gave an effective dielectric function of the Ag-SiO2 composite film, reproduced the deformation of the dispersion curve of the SPP. The deformation of the dispersion observed experimentally was qualitatively explained by the behavior of the effective dielectric function of the Ag-SiO2 composite film. 相似文献
2.
Electrooptic reflection with surface plasmons is studied both experimentally and theoretically. An attenuated total reflection (ATR) geometry is used in which a quartz electrooptic crystal onto which a thin Ag film has been evaporated is contacted to the hypotenuse face of a high-index prism. Modulation in the ATR of an He–Ne beam near the angle for surface plasmon excitation is observed when a low-frequency electric field is applied to the quartz crystal. Experiments have been done with both single and multiple boundary surface waves. The angular spectra show phase reversal structure due to the interference of the modulated reflected wave with the ATR wave. The modulated reflectance is calculated directly from a well-known solution to the boundary value problem in nonlinear optics. Good quantitative agreement with the observations is obtained. 相似文献
3.
Toshihiro Okamoto Kenji KakutaniTomomi Yoshizaki Masanobu HaraguchiMasuo Fukui 《Surface science》2003,544(1):67-73
We have proposed a way to evaluate the reflectance of surface plasmon polaritons (SPP) at a Ag step barrier from an experiment using the attenuated total reflection structure consisting of ultra-thin metal films sandwiched by dielectrics with nearly identical refractive index. At a wavelength of 632.8 nm, for a long-range SPP (L-SPP) excited in a Ag film of 5.7 nm in thickness, the reflectance at Ag step barriers of 766 nm in height was evaluated to be 7.9 × 10−2. 相似文献
4.
J.-Y. Chu T.-J. Wang J.-T. Yeh M.-W. Lin Y.-C. Chang J.-K. Wang 《Applied Physics A: Materials Science & Processing》2007,89(2):387-390
We report a near-field study of the excitation and propagation of surface plasmon on ordered Ag elliptical hole arrays with
a scattering-type scanning near-field optical microscope. Strong dipole-like local plasmon is identified at each individual
hole from near-field optical intensity and phase images. The excitation of the local plasmon at the elliptical hole is found
to follow polarization excitation constraint. The coherent superposition of these local plasmon waves to form an extended
surface plasmon wave propagating to an adjacent hole array is observed directly. The near-field results are consistent with
the results obtained from far-field extraordinary transmission measurements.
PACS 42.25.Bs; 42.25.Hz; 42.25.Ja; 42.25.Kb; 07.79.Fc 相似文献
5.
《Surface science》1986,171(1):135-145
The emission of narrowband radiation, sharply peaked at ≈ 3.8 eV and strongly p-polarised, is observed from nominally smooth AlAl2O3Ag tunnel junctions under high applied bias (> 4 V). The peak emission energy actually displays a weak, but significant dependence on the angle of emission. This observation implies that the emission is primarily due to the decay of a radiative surface plasmon polariton mode excited in the Ag electrode, and is not, as has been suggested, due to Ag volume plasmon-photon coupling. Also, the results on angular distribution of the emission intensity are consistent only with radiative surface plasmon emission. 相似文献
6.
The influence of a longitudinal component in surface plasma waves propagating along the boundary between a plasma and vacuum has been investigated theoretically. It is found that the inclusion of the longitudinal component significantly modifies the dispersion relation for surface plasmons. In particular, it is shown that a surface plasmon can have any frequency in the interval from zero to the bulk plasma frequency. 相似文献
7.
相对于单一金属纳米材料,二金属复合纳米材料具有更大的潜在应用价值.基于时域有限差分方法,研究了SiO2-Ag-Au和SiO2-Au-Ag二金属三层纳米管的消光光谱,并对其局域表面等离激元共振(Localized Surface Plasmon Resonance,LSPR)特性进行了分析.研究发现,内核尺寸变大将导致上述两种金属纳米管LSPR峰红移;内层金属及外层金属壳层厚度增大均会导致其LSPR峰蓝移.银壳厚度变化对纳米管LSPR的调制作用大于金壳厚度变化造成的影响.上述现象可以利用等离激元杂化理论及自由电子和振荡电子变化的竞争机制进行分析. 相似文献
8.
We generate self-collimating surface plasmon beams in a doubly periodic plasmonic grating. The self-collimation effect is understood from the local anisotropy of the isofrequency surface of the grating in the vicinity of the bandgap. The properties of the beams are analyzed by leakage radiation microscopy and show to an unprecedented level significantly reduced diffraction as compared with plasmon beams propagating on a flat metal film. 相似文献
9.
10.
M. Merschdorf W. Pfeiffer A. Thon S. Voll G. Gerber 《Applied Physics A: Materials Science & Processing》2000,71(5):547-552
Two-photon photoemission spectroscopy using femtosecond laser pulses is used to investigate the excitation and decay mechanisms
of the surface plasmon resonance in Ag nanoparticles grown on graphite. The resonant excitation of this collective excitation
leads to a two-orders-of-magnitude-enhanced two-photon photoemission yield from a graphite surface with Ag nanoparticles compared
to the yield from pure graphite. From the shape of the photoemission spectra, the polarization dependence of the photoemission
yield and the excitation probabilities for different excitation pathways we conclude that excitation with 400-nm femtosecond
laser pulses leads to the coherent multiple excitation of the surface plasmon in the Ag nanoparticles. This multiply excited
plasmon mode can decay via the coupling to a single-particle excitation leading to the emission of an electron if its final
state is located in the continuum. The surface plasmon in metallic nanoparticles is a model system to investigate collective
excitations in multiphoton processes.
Received: 26 June 2000 / Accepted: 2 September 2000 / Published online: 12 October 2000 相似文献
11.
A highly-sensitive grating-based surface plasmon resonance (SPR) sensor is proposed. The angular interrogation method has been used to study the performance of the sensor, and high sensitivity is obtained if the ?1st diffraction order is used to excite surface plasmon (SP). The sensitivity as well as the width of the SPR curves and reflective amplitude is considered for designing the sensor. Compared with the conventional gold (Au)-based or silver (Ag)-based SPR sensor, it is found that the aluminum (Al)-based sensor has the best performance. The oxidation problem of an Al-based SPR sensor has been addressed by coating it with an ultrathin gold film on the surface. Numerical simulations based on rigorous coupled wave analysis (RCWA) show that the sensitivity of the optimized sensor is 245°/RIU (degree per refractive index unit). 相似文献
12.
D. Mihalache D. -M. Baboiu M. Ciumac L. Torner J. P. Torres 《Optical and Quantum Electronics》1994,26(8):857-863
Hybrid surface plasmon polaritons propagating in a new configuration comprising an ultrathin metal film bounded by a positive birefringent crystal on one side and a glass material on the other side are investigated. The results show that the conditions for existence of such hybrid surface plasmon polaritons have a strong dependence on the structure parameters. This feature opens the way for a new type of optical sensor with directional sensitivity. 相似文献
13.
Coupling interaction between a single emitter and the propagating surface plasmon polaritons in a graphene microribbon waveguide
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The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon (GMR) waveguide is investigated by numerical calculations, where the emitter is situated above the GMR or in the same plane of the GMR, The results reveal a multimode coupling mechanism for the strong interaction between the emitter and the propagating plasmonic waves in graphene. When the emitter is situated in the same plane of the GMR, the decay rate from the emitter to the surface plasmon polaritons increases more than 10 times compared with that in the case with the emitter above the GMR. 相似文献
14.
By use of photoemission-into-electrolyte spectroscopy on a cylindrical silver single crystal the optical excitation and decay of surface plasmons on high index faces of silver has been studied. After electrochemical roughening the surface plasmon excitation showed a pronounced polarization dependence. Photoemission, induced by the decay of the excited plasmon. was only detected for orientations very close to the densely packed Ag(111) face. 相似文献
15.
用热蒸发的方法制备了纳米Ag材料,并用扫描电子显微镜对纳米粒子进行了形貌的表征,通过紫外—可见分光光度计得到Ag纳米粒子的透过谱,得到了Ag纳米粒子的表面等离子体共振的峰值位置.以罗丹明6G为探针分子测定Ag纳米粒子衬底的表面增强拉曼散射效应,通过拉曼散射光谱与透过谱研究了由表面等离子体激元的强极化场引起的表面增强拉曼散射效应,结合透过谱与拉曼增益因子提出了一种描述表面等离子体光学和电学特性的方法,并结合扫描电镜的结果给出了不同结构的纳米Ag材料对表面等离子体激元强度的影响.
关键词:
热蒸发
纳米Ag材料
表面等离子体
表面增强拉曼散射 相似文献
16.
On the fluorescence enhancement mechanism of Er3+ in germanate glass containing silver particles
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The spectral properties of trivalent erbium ions(Er3+) are systematically studied in a melt-quenched germanate glass(60 GeO2-20PbO-10BaO-10K2O-0.1Ag2O) containing silver(Ag) particles.Thermal treatment of the material leads to the precipitation of Ag particles as observed by transmission electron microscopy and confirmed by absorption spectrum for the obvious surface plasmon resonance peak of Ag particles.The fluorescence from Er3+ in the 10-min-annealed sample with Ag particles is found to be 4.2 times enhanced compared with the unannealed sample excited by 488-nm Ar+ laser.A comparison is made between a spectral study performed on the unannealed Er3+-doped sample and the one annealed for 20 min.The data of absorption cross section and Judd-Ofelt intensity parameters show the agreement between the two samples no matter whether there are Ag particles,indicating that the introduction of Ag particles by post-heat treatment has no effect on the crystal field environment of Er3+ ions.The fluorescence enhancement is attributed to the surface plasmon oscillations of Ag particles in germanate glass. 相似文献
17.
《Current Applied Physics》2014,14(9):1287-1292
Surface Plasmon resonance of Ag nanoparticles in the vicinity of a high impedance surface is investigated. Mushroom-like nanostructures were vertically grown on silicon substrate to form a high impedance surface operating in the range of optical frequencies. Formation of Ag nanoparticles on the fabricated high impedance surface was realized using plasma bombardment process. Optical measurements show an enhancement in the surface plasmon resonances of Ag nanoparticles. Also it was shown that the plasmon resonance peak of the Ag nanoparticles shifts to blue when Ag nanoparticles approach to the high impedance surface. 相似文献
18.
《Solid State Communications》1987,64(3):375-378
Surface enhanced Raman scattering from copper phthalocyanine thin films deposited onto Ag films roughened by underlayers of gas-evaporated Si particles was investigated. The surface roughness was systematically varied by varying the average size of Si particles. Results of quantitative intensity measurements indicate that there exists an optimum surface roughness depth for SERS. The maximum enhancement factor obtained is ≈1.5 x 104 and a crude estimate of the optimum roughness depth is of the order of 100 Å. The origin of presently observed enhancement is thought to be purely electromagnetic, involving the excitation of the surface plasmon modes via the surface roughness. 相似文献
19.
The lifetime of the surface plasmon in sputtered Ag ultrathin films on Cu(111) was investigated by high‐resolution electron energy loss spectroscopy measurements. The linewidth of the surface plasmon was found to follow a square‐root dependence on the fluence. Such finding allows the tuning of the lifetime of the plasmonic excitation upon sputtering and has general implications in plasmon‐based spectroscopies and in plasmon‐mediated processes across the films and at their surfaces. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
20.
On the assumption that the resonant surface plasmons on a spherical nanoparticle are formed by standing waves of two counter-propagating surface plasmon waves along the surface, by using Mie theory simulation, we find that the dispersions of surface plasmon resonant modes supported by silver nanospheres match with those of the surface plasmons on a semiinfinite medium-silver interface very well. This suggests that the resonant surface plasmons of a metal nanosphere can be treated as a propagating surface plasmon wave. 相似文献