表面等离激元导论（讲稿）Introduction to plasmonics

表面等离激元导论Introductionto plasmonics研究：金属和介质表面以及纳米金属颗粒的光学性质。解读：Surfaceplasmonpolariton（SPP)Surface:金属和介质的界面Plasmon：金属界面自由电子的集体振荡，借用等离子的概念Polariton:模式属于:Mesoscopicoptics,nanooptics,nanophotonics,nearfieldoptics古英2011年3月ygu@pku.edu.cn

1 表面等离激元导论 Introduction to plasmonics 解读： Surface plasmon polariton （SPP) Surface: 金属和介质的界面 Plasmon: 金属界面自由电子的集体振荡， 借用等离子的概念 Polariton: 模式 属于： Mesoscopic optics, nano optics, nano photonics, near field optics 研究： 金属和介质表面以及纳米金属颗粒 的光学性质。 古英 ygu@pku.edu.cn 2011年3月

Differencebetweensurfaceplasmon(SP)andsurfaceplasmonpolaritons(SPP)"a trapped surface mode which has electromagnetic fieldsdecaying into both media but which, tied to the oscillatorysurface charge density, propagates along the interface"R.J.Sambles1991E（O)'we are dealing with a resonant excitation of a coupledstate between the plasma oscillations and the photons, i.e.,the plasmon surface polariton'W.Knoll19912

2 Difference between surface plasmon (SP) and surface plasmon polaritons (SPP)

dc)Wavelength (μm)21.510.5Colloidalabsorptic1.2Mietheory1.0thin film absorptionotoesso0(ne)90.8-ouegb)0.60.4.20.20.0-0.51015202.53.03.5404.55.0Energy (eV)Fig.1l(a)by exampleof theLycurgus cup (Byzantine empire,4th century A.D.).The glass cup, on display in the BritishMuseum, shows a striking red color when viewed in trans-mittedlight,while appearinggreen inreflection.Thispecu-liarbehaviorisduetosmallAunanoparticlesembeddedintheglass[Fig.1(b)l,whichshowastrongopticalabsorptionof light in the green part of the visible spectrum [Fig.1(e)]3Plasmonics:Localizationandguidingofelectromagneticenergy in metal/dielectricStefanA.MaierandHarryA.Atwater,JOURNALOFAPPLIEDPHYSICS98,0111012005

3 Plasmonics: Localization and guiding of electromagnetic energy in metal/dielectric Stefan A. Maier and Harry A. Atwater, JOURNAL OF APPLIED PHYSICS 98, 011101 2005

五个部分：第一章SPP的发展简史第二章SPP的基本概念及物理第三章介观光学的理论方法第四章SPP的科学前沿和应用第五章SPP和量子体系的交叉研究参考文献纳米结构制备及实验光路等略讲作业：report（三到五页）

4 五个部分： 第一章 SPP的发展简史 第二章 SPP的基本概念及物理 第三章 介观光学的理论方法 第四章 SPP的科学前沿和应用 第五章 SPP和量子体系的交叉研究 参考文献 作业：report （三到五页） 纳米结构制备及实验光路等略讲

第一章SPP的发展简史Wood'sanomalies,1902Fig.1.OnaRemarkableCaseofUnevenDistributionofLightinaDiffractionGratingSpectrumRWWood1902Proc.Phys.Soc.London182695SURFACE-PLASMONRESONANCEEFFECTINGRATINGDIFFRACTIONRITCHIERH,ARAKAWAET,COWANJJ,etal（1968）PRL,21,1530

5 Wood’s anomalies，1902 第一章 SPP的发展简史 On a Remarkable Case of Uneven Distribution of Light in a Diffraction Grating Spectrum R W Wood 1902 Proc. Phys. Soc. London 18 269 SURFACE-PLASMON RESONANCE EFFECT IN GRATING DIFFRACTION RITCHIE RH, ARAKAWA ET, COWAN JJ, et al （1968） PRL, 21 , 1530

Mietheory,1908Exactsolutionof sphere,sphericalsymmetrystructureAbsorption,scattering,andextinctionZenneck(1907)&Sommerfeld(1909)Demonstrated(theoretically)thatradiofrequencysurfaceEMwaves occur attheboundary oftwomedia when onemedium iseithera"lossy"dielectric,orametal,and theother is aloss-freemedium.They also suggested that it is the"lossy"(imaginary)part of thedielectricfunctionthatisresponsibleforbindingtheEM wavetotheinterface

6 Mie theory , 1908 Exact solution of sphere, spherical symmetry structure Absorption, scattering, and extinction

Fano(1939)Suggested that surface EM waves were responsible for the strikinganomalies in the continuous source diffraction spectra of metallicgratings-'Wood'sAnomalies'According to Fano : Surface EM wave, at metal-air interfaces.areevanescent waves whose wave vectors are greater than those of theincident and diffracted bulk EM waves, and that the gratingaugments the wave vector of the incident EM waves enabling themtocouplewiththe surfaceEMwaves.7

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Fano suggested:1. surface EM waves at lossy-dielectric-air interfaces at radiofrequencies (Zenneck-Sommerfeld waves)2. surface EM waves at metal-air interfaces in the optical region(Fanomodes)3. loss-free dielectric/air interfaces (Brewster anle EM waves)"'represent for media of different electrical properties the samesingular case defined by the same mathematical equation'8

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Ritchie(1957)Demonstratedtheoreticallytheexistenceof Surfaceplasmaexcitations (surfaceplasmons)at ametal surfaceStern(1958)Showed(theoretically)thatsurfaceEM wavesatametallic surfaceinvolved EM radiation coupled to surface plasmons.Derived, for the first time, the dispersion relations for surface EMwavesatmetal surfaces9

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Powell&Swan(1960)Observedtheexcitationof surfaceplasmons atmetal interfacesusingelectrons.0tto(1968)Devised the ATR (prism coupling)methodforthe coupling of bulkEMwaves(optical)tosurfaceEMwaves.Kretschmann(1971)Modified the Otto geometry is now the most widely used devicegeometry.Knoll（(1989)Introduced the technique of Surface Plasmon Microscopy10

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