北京大学：《微纳光学》课程教学课件（超材料光学讲稿）第二章 表面等离激元的发展、前沿及应用

第二章表面等离激元的发展、前沿及应用(1-43)2.1表面等离激元发展简史2.2表面等离激元的应用2.2.1表面等离激元（SPP）波导（45-65）及应用(SPR)(67-96)2.2.2表面等离激元共振(98-112)2.2.3周期性结构中SPP性质2

2 第二章 表面等离激元的发展、前沿及应用 2.1 表面等离激元发展简史 （1-43） 2.2 表面等离激元的应用 2.2.1 表面等离激元（SPP）波导（45-65） 2.2.2 表面等离激元共振（SPR）及应用（67-96） 2.2.3 周期性结构中SPP性质 （98-112）

金和银的介电常数值0gold10silver520Gold330Silver240-50.60060040080040080020010002001000wavelengthwavelengthOpticalConstantsof theNobleMetalsP.B,Johnson and R.W.ChristyPRB,6,4370(1972)3

3 200 400 600 800 1000 -50 -40 -30 -20 -10 0 200 400 600 800 1000 0 1 2 3 4 5 6 7 Real dielectric constant wavelength Gold Silver Imaginay dielectric constant) wavelength gold silver PRB, 6, 4370 (1972). 金和银的介电常数值

（按年代）2.1表面等离激元发展简史Wood'sanomalies,1902Fig.1,VELENGTHOnaRemarkableCaseof UnevenDistributionof Light inaDiffractionGratingSpectrumRWWood1902Proc.Phys.Soc.London18269SURFACE-PLASMONRESONANCEEFFECTINGRATINGDIFFRACTIONRITCHIERH,ARAKAWAET,COWANJJ,etal（1968）PRL,21,1530

4 Wood’s anomalies，1902 2.1 表面等离激元发展简史（按年代） 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,spherical symmetrystructureAbsorption,scattering,andextinctionZenneck(1907)&Sommerfeld(1909)Demonstrated(theoretically)thatradiofrequencysurfaceEMwaves occurattheboundary of twomediawhen onemediumiseither a"lossy"dielectric,ora metal,and theother is a loss-freemedium.They also suggested that it is the"lossy"(imaginary)part ofthedielectricfunction thatis responsibleforbindingtheEMwavetotheinterface

5 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 surfaceEM waves.6

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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(Fano modes)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'7

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Ritchie(1957)Demonstrated theoretically the existence of Surfaceplasmaexcitations (surfaceplasmons)at ametal surfaceStern(1958)Showed (theoretically) that surface EM waves at a metallic surfaceinvolved EM radiation coupled to surface plasmons.Derived,for the first time, the dispersion relations for surfaceEMwaves atmetal surfaces8

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Powell&Swan(1960)Observedtheexcitationof surfaceplasmons atmetal interfacesusing electrons.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 Microscopy9

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ExtraordinaryopticaltransmissionT.W.Ebbesengroup,1998StartpointofSPPBottleneck:lowlighttransmittivityofapertures smallerthanthewavelengthofincidentphotonHole arrays in silver film:metalfilmthicknessPeriodicity of holessaoScale of holesdsResults:ExtraordinarytransmissionMaximumat 2/d~10Influenceoft(inAPL)Explanation:Coupling of light and plasmons0.51.522.51Wavelength/period10ExtraordinaryopticaltransmissionthroughsubwavelengthholesT.W.Ebbesenetal,NATURE/VOL39112FEBRUARY1998

10 Bottleneck: low light transmittivity of apertures smaller than the wavelength of incident photon Hole arrays in silver film: metal film thickness t Periodicity of holes a0 Scale of holes d Results: Extraordinary transmission Maximum at /d~10 Influence of t (in APL) Explanation: Coupling of light and plasmons Extraordinary optical transmission T.W.Ebbesen group , 1998 Extraordinary optical transmission through subwavelength holes T.W. Ebbesen et al, NATURE |VOL 391 | 12 FEBRUARY 1998 Start point of SPP

Beaming lightfromabull's eyes structureT.W.Ebbesen group, 2002ProgressworkBTo solve:lightdiffracts inalldirections whenanapertureisO.Fsmall.10.0Bull's eye of Ag film:0.2thickness300nm0.0y500nmGroove periodicity500400600700800900Wavelength (nm)DcAnddepth60nmHolediamter250nm0.6Results:Beaming lightAngie (deg)Explanation:Couplingof lightand plasmons11Beaming lightfromasubwavelengthhole,T.W.Ebbesenetal,Science,297,820(2002)

11 Beaming light from a bull’s eyes structure T.W.Ebbesen group , 2002 Progress work Beaming light from a subwavelength hole, T.W. Ebbesen et al, Science,297,820(2002) To solve: light diffracts in all directions when an aperture is small. Bull’s eye of Ag film: thickness 300nm Groove periodicity 500nm And depth 60nm Hole diamter 250nm Results: Beaming light Explanation: Coupling of light and plasmons