Optical Antennas

"This consistent and systematic review of recent advances in optical antenna theory and practice brings together leading experts in the fields of electrical engineering, nano-optics and nano-photonics, physical chemistry and nanofabrication. Fundamental concepts and functionalities relevant to optical antennas are explained, together with key principles for optical antenna modelling, design and characterisation. Recognising the tremendous potential of this technology, practical applications are also outlined. Presenting a clear translation of the concepts of radio antenna design, near-field optics and field-enhanced spectroscopy into optical antennas, this interdisciplinary book is an indispensable resource for researchers and graduate students in engineering, optics and photonics, physics and chemistry"-- Provided by publisher Cover......Page 1 Title......Page 5 Copyright......Page 6 Dedication......Page 7 Contents......Page 9 Preface......Page 17 Contributors......Page 20 Notation......Page 24 Part I FUNDAMENTALS......Page 27 1.1 The near-field......Page 29 1.2 Energies and photons......Page 30 1.4 Scanning near-field optical microscopy......Page 31 1.5 Problems of near-field optical microscopy......Page 33 1.7 Optical antennas......Page 34 1.8 Conclusions and outlook......Page 36 2.1 Introduction......Page 37 2.2 Nanoantennas and optical nanocircuits......Page 38 2.2.1 Optical nanocircuit theory......Page 39 2.2.2 Nanoantennas as optical lumped elements......Page 40 2.2.3 Other quantities of interest for optical antenna operation......Page 43 2.3.1 Loading, impedance matching and optical wireless links......Page 44 2.3.2 Optimizing bandwidth and sensitivity with nanoloads......Page 47 2.3.3 Optical nonlinearities as variable nanoloads......Page 50 Acknowledgments......Page 51 3.1 Introduction......Page 52 3.2.1 Definition......Page 53 3.2.2 A vacuum......Page 54 3.2.3 A microcavity......Page 56 3.2.4 A dipolar nanoantenna......Page 57 3.2.5 Comparison of a microcavity and a nanoantenna......Page 58 3.2.6 Ohmic and radiative losses......Page 59 3.3.1 A two-level system......Page 60 3.3.2 Impedance and multiple scattering......Page 62 General case: equivalent circuit and eigenfrequencies......Page 63 Weak coupling regime......Page 64 Strong coupling regime......Page 65 3.4.2 Conjugate impedance matching condition......Page 67 3.4.3 Maximum absorption by a metallic nanoparticle......Page 68 3.4.4 Fluorescence enhancement by metallic nanoparticles......Page 69 3.5 Conclusions......Page 71 4.1 Introduction......Page 72 4.2.1 Configuration......Page 76 4.2.2 Theory......Page 77 4.2.3 Coated-nanoparticle materials and gain models......Page 78 4.3 Results and discussion......Page 79 4.3.2 Near-field results......Page 80 4.3.3 Influence of the dipole location......Page 82 4.3.4 Additional effects – transparency......Page 84 4.3.5 Additional coated-nanoparticle cases......Page 85 4.4.1 Nanoparticle model......Page 86 4.4.2 Results and discussion......Page 87 4.5 Conclusions......Page 89 5.1.1 Field enhancement......Page 90 5.1.2 Spectral response......Page 91 5.1.3 Shape......Page 93 Aspect ratio......Page 95 Sharpness......Page 97 Coupling......Page 98 5.2 Surface-enhanced Raman scattering......Page 99 5.3 Surface-enhanced infrared absorption......Page 101 5.4 Metal-enhanced fluorescence......Page 102 5.5 Quantum effects in nanoantennas......Page 105 6.1.1 Optical antennas......Page 107 Definition......Page 108 Optical antennas as cavities......Page 109 Excitation, emission and dissipation rates......Page 110 6.1.3 Resonant coupling of antenna and emitter......Page 113 6.2.2 The monopole antenna case......Page 115 Localization: role of the antenna excitation field......Page 116 Enhancement: role of the antenna resonance......Page 118 The monopole antenna case......Page 119 The dipole antenna case......Page 121 The dipole antenna case......Page 122 The Yagi–Uda antenna case......Page 123 6.4 Conclusions and outlook......Page 125 Quantum optics......Page 126 Classical optics......Page 127 Near-field microscopy......Page 128 7.2 Microcavities......Page 129 7.3 Antennas......Page 130 7.3.1 Small antennas......Page 131 7.4.1 Planar antennas......Page 133 7.4.2 Microcavities......Page 134 7.4.3 Plasmonic nanoantennas......Page 135 7.4.4 Metallo-dielectric hybrid antennas......Page 137 7.5.2 Plasmonic nanoantennas......Page 139 7.5.3 Planar antennas......Page 140 7.6 Antennas immersed in vacuum fluctuations: Casimir and van der Waals interactions......Page 142 7.7 Scanning near-field optical microscopy......Page 144 7.8 Outlook......Page 146 Acknowledgments......Page 147 8.1 Introduction......Page 148 8.2.1 Origin of optical nonlinearities in nanoantennas......Page 149 8.2.2 Nonlinear susceptibilities of optical materials......Page 152 8.3.1 Nanoscale and macroscale nonlinear phenomena......Page 153 8.3.3 Nonlinear polarization in nanoparticles......Page 154 8.4 Nonlinearities in coupled antennas and arrays......Page 155 8.4.1 Enhancement of metal nonlinearities......Page 156 8.4.2 Enhancement of nonlinearities in surrounding media......Page 157 8.4.3 TPL nonlinear microscopy of coupled particles......Page 158 8.5 Conclusions and outlook......Page 159 9.1 Introduction......Page 161 9.2 Local-field control principles......Page 164 9.2.1 Fundamental quantities......Page 165 9.2.2 Spectral enhancement......Page 166 9.2.3 Local polarization-mode interference......Page 168 9.2.4 Local pulse compression......Page 169 9.2.5 Optimal control......Page 170 9.2.6 Analytic optimal control rules......Page 172 9.2.7 Time reversal......Page 174 9.2.8 Spatially shaped excitation fields......Page 175 9.3.1 Spatial excitation control......Page 176 9.3.2 Spatiotemporal excitation control......Page 178 9.3.3 Propagation control......Page 179 9.4.1 Space–time-resolved spectroscopy......Page 180 9.4.3 Unconventional excitations......Page 181 9.5 Conclusions and outlook......Page 182 Part II MODELING, DESIGN AND CHARACTERIZATION......Page 183 10.1 Introduction......Page 185 10.2 The numerical solution of Maxwell equations......Page 186 10.2.1 Finite-difference time-domain method......Page 187 10.2.2 Finite-differences method......Page 188 10.2.3 Finite-elements method......Page 189 10.2.4 Volume integral-equation method......Page 191 10.2.5 Boundary-element method......Page 192 10.3 Validity checks......Page 194 10.4 Modeling realistic optical antennas......Page 195 10.5 Tuning the antenna properties......Page 197 Acknowledgments......Page 200 11.1 Introduction......Page 201 11.2 Quantum effects on the near-field......Page 203 11.3 Plasmon–exciton hybridization......Page 207 11.4 Near-field effects on spectroscopy......Page 213 11.4.1 Surface-enhanced Raman scattering......Page 214 11.4.2 Surface-enhanced fluorescence......Page 217 11.5 Near-field effects on molecular photochemistry......Page 218 11.5.2 Photochemical enhancement mechanism......Page 219 11.6 Conclusions and outlook......Page 222 12.1 Introduction......Page 223 12.2 Theoretical background......Page 225 12.3.1 Sphere dimers......Page 229 12.3.2 Nano-rods......Page 233 12.3.3 Cylinders......Page 235 12.4 Enhancement and localization versus distance in particle dimers......Page 237 12.5 Conclusions......Page 239 13.1 Introduction......Page 241 13.2 Fabrication of single-crystalline antennas......Page 242 13.2.1 Role of the dielectric function......Page 243 13.2.2 Effects of geometry and multicrystallinity......Page 245 13.2.3 Fabrication issues......Page 246 13.2.4 Single-crystalline nanostructures......Page 247 13.3.1 Far-field scattering......Page 249 13.3.2 Determining the near-field intensity enhancement......Page 250 13.3.3 Emission directivity and coupling to quantum emitters......Page 256 13.4 Conclusions and outlook......Page 258 14.1 Introduction......Page 260 14.2.1 Instrumental setup......Page 262 14.2.2 The photoemission process......Page 264 14.3.1 Local near-field mapping......Page 266 14.3.3 Observing and controlling the near-field distribution......Page 270 14.3.4 Nonlinearities on structured surfaces......Page 273 14.4 Time-resolved two-photon photoemission......Page 274 14.4.1 Phase-averaged time-resolved PEEM......Page 276 14.4.2 Phase-resolved PEEM......Page 278 14.5.2 Magneto-plasmonics......Page 279 14.6 Conclusions and outlook......Page 280 Acknowledgments......Page 281 15.1 Introduction......Page 282 15.2.1 The array factor......Page 283 15.2.2 Two-dimensional planar arrays and phased arrays......Page 285 15.2.3 Directionality enhancement......Page 286 15.3.1 Effective antenna length......Page 287 15.4 The optical Yagi–Uda antenna – linear array of plasmonic dipoles......Page 288 15.4.2 Design of receiving optical Yagi–Uda antennas......Page 290 15.4.3 Characterization of receiving optical Yagi–Uda antenna......Page 291 15.5.1 Characterization of planar optical antenna arrays......Page 294 15.5.2 Fabricating three-dimensional nanoantennas......Page 296 15.5.3 Optical properties......Page 297 15.5.4 Experimental characterization......Page 298 15.6 Applications of optical antenna arrays......Page 300 15.6.1 Phased arrays for optical wavelengths......Page 301 15.6.2 Optical antenna links......Page 302 16.1 Introduction......Page 303 16.2 Conventional methods to create nanoantennas......Page 305 16.3 Soft nanolithography......Page 306 16.3.3 Nanopatterned template......Page 307 16.3.4 Optical antenna arrays......Page 308 16.4 Strongly coupled nanoparticle arrays......Page 309 16.5 Metal–insulator–metal nanocavity arrays......Page 311 16.6 Three-dimensional bowtie antenna arrays......Page 315 16.7 Conclusions and outlook......Page 319 17.1 Introduction......Page 320 17.2 Self-assembled magnetic clusters......Page 321 17.3 Plasmonic Fano-like resonances......Page 329 17.4 DNA cluster assembly......Page 337 17.5 Conclusions and outlook......Page 342 Acknowledgments......Page 343 Part III APPLICATIONS......Page 345 18.1 Introduction......Page 347 18.2 Coupling plasmonic antennas to semiconductors......Page 348 18.3 Plasmonic antennas for information technology and energy harvesting......Page 358 18.4 Operation of semiconductor-based optical antennas......Page 360 18.5 Semiconductor antennas for information technology and energy harvesting......Page 362 18.6 Conclusions and outlook......Page 364 Acknowledgments......Page 365 19.1 Introduction......Page 366 19.2.1 Bulk sensitivity......Page 368 Substrate effects......Page 370 19.2.2 Molecular sensing......Page 373 Relating resonance shifts to the number of adsorbed molecules......Page 374 Direct comparison between sensing platforms......Page 375 Ensemble and single particle assays......Page 376 19.3.1 Fano resonances......Page 377 19.3.2 Alternative sensing schemes......Page 379 19.3.4 Plasmonic sensing for materials science......Page 380 19.4 Conclusions and outlook......Page 381 20.1 Introduction......Page 382 20.2 The diffraction limit and spatial resolution......Page 383 20.3 Evanescent waves and metals......Page 384 20.3.2 Optical antennas......Page 385 20.4 Tip-enhanced Raman spectroscopy......Page 386 20.4.1 Spatial resolution in TERS......Page 388 20.4.2 Imaging intrinsic properties through TERS......Page 389 20.5.1 Combining optical antennas with mechanical effects......Page 390 20.6 Optical antennas as nanolenses......Page 392 20.7 Conclusions and outlook......Page 393 21.1 Introduction......Page 395 21.2.1 Single apertures......Page 396 21.2.2 Single apertures surrounded by surface corrugations......Page 398 21.2.3 Aperture arrays......Page 400 Single molecule fluorescence spectroscopy in liquids......Page 402 Live cell membrane investigations......Page 404 Trapping......Page 405 Surface plasmon resonance spectroscopy......Page 406 Surface-enhanced Raman spectroscopy......Page 408 21.4.2 Nanosources......Page 409 Acknowledgments......Page 411 References......Page 413 Index......Page 472 Machine generated contents note: Part I. Fundamentals: 1. From near-field optics to optical antennas D. Pohl; 2. Optical antenna theory, design and applications A. Alù and N. Engheta; 3. Impedance of a nanoantenna F. Marquier and J-J. Greffet; 4. Where high-frequency engineering advances optics: active nanoparticles as nanoantennas R. W. Ziolkowski, S. Arslanagić and J. Geng; 5. Optical antennas for field-enhanced spectroscopy J. Aizpurua and R. Esteban; 6. Directionality, polarization and enhancement by optical antennas T. H. Taminiau, A. Curto and N. F. van Hulst; 7. Antennas, quantum optics and near-field microscopy V. Sandoghdar, M. Agio, X-W. Chen, S. Götzinger and K-G. Lee; 8. Nonlinear optical antennas H. Harutyunyan, G. Volpe and L. Novonty; 9. Coherent control of nano-optical excitations W. Pfeiffer, M. Aeschlimann and T. Brixner; Part II. Modeling, Design and Characterization: 10. Computational electrodynamics for optical antennas O. J. F. Martin; 11. First-principles simulations of near-field effects J. L. Payton, S. M. Morton and L. Jensen; 12. Field distribution near optical antennas at the subnanometer scale C. Pecharromán; 13. Fabrication and optical characterization of nanoantennas J. Prangsma, P. Biagioni and B. Hecht; 14. Probing and imaging of optical nanoantennas with PEEM P. Melchior, D. Bayer and M. Aeschlimann; 15. Fabrication, characterization and applications of optical antenna arrays D. Dregely, J. Dorfmüller, M. Hentschel and H. Giessen; 16. Novel fabrication methods for optical antennas W. Zhou, J. Y. Suh and T. W. Odom; 17. Plasmodic properties of colloidal clusters: towards new nanomaterials and optical circuits J. A. Fan and F. Capasso; Part III. Applications: 18. Optical antennas for information technology and energy harvesting M. L. Brongersma; 19. Nanoantennas for refractive-index sensing T. Shegai, M. Svedendahl, S. Chen, A. Dahlin and M. Ka;ll; 20. Nanoimaging with optical antennas P. Verma and Y. Saito; 21. Aperture optical antennas J. Wenger.