The updated third edition of the only textbook on colour
The revised third edition of Colour and the Optical Properties of Materials focuses on the ways that colour is produced, both in the natural world and in a wide range of applications. The expert author offers an introduction to the science underlying colour and optics and explores many of the most recent applications. The text is divided into three main sections: behaviour of light in homogeneous media, which can largely be explained by classical wave optics; the way in which light interacts with atoms or molecules, which must be explained mainly in terms of photons; and the interaction of light with insulators, semiconductors and metals, in which the band structure notions are of primary concern.
The updated third edition retains the proven concepts outlined in the previous editions and contains information on the significant developments in the field with many figures redrawn and new material added. The text contains new or extended sections on photonic crystals, holograms, flat lenses, super-resolution optical microscopy and modern display technologies. This important book:
- Offers and introduction to the science that underlies the everyday concept of colour
- Reviews the cross disciplinary subjects of physics, chemistry, biology and materials science, to link light, colour and perception
- Includes information on many modern applications, such as the numerous different colour displays now available, optical amplifiers lasers, super-resolution optical microscopy and lighting including LEDs and OLEDs
- Contains new sections on photonic crystals, holograms, flat lenses, super-resolution optical microscopy and display technologies
- Presents many worked examples, with problems and exercises at the end of each chapter
Written for students in materials science, physics, chemistry and the biological sciences, the third edition of Colour and The Optical Properties of Materials covers the basic science of the topic and has been thoroughly updated to include recent advances in the field.
Table of Contents
Preface xv
About the Companion Website xvii
1 Light and Colour 1
1.1 Light and Colour 1
1.1.1 Light rays 1
1.1.2 Light waves 2
1.1.3 Photons 3
1.1.4 Energy levels 4
1.1.5 Waves and particles 5
1.1.6 Colour 6
1.2 Light Waves 6
1.3 Light Waves and Colour 8
1.4 Interference 9
1.4.1 Two waves with the same wavelength 9
1.4.2 Two waves with different wavelengths 10
1.4.3 Phase and group velocity 11
1.4.4 Light pulses 12
1.4.5 Superluminal and subluminal light 14
1.5 Light Sources 15
1.6 Incandescence 16
1.6.1 Incandescence and black-body radiation 16
1.6.2 The colour of incandescent objects 17
1.7 Luminescence 18
1.8 Laser Light 20
1.8.1 Emission and absorption of radiation 20
1.8.2 Energy-level populations 22
1.8.3 Rates of absorption and emission 23
1.8.4 Cavity modes 25
1.8.5 Coherence length and bandwidth 26
1.8.6 Supercontinuum light 27
1.9 Vision 28
1.10 Colour Perception 33
1.11 Additive Coloration 34
1.12 Subtractive Coloration 37
1.13 The Interaction of Light with a Material: Appearance 39
1.13.1 Reflection 39
1.13.2 Diffuse reflectance 40
1.13.3 Elastic scattering 41
1.13.4 Inelastic scattering 42
1.13.5 Absorption 42
1.13.6 Attenuation 43
1.13.7 Structural colour, iridescence, and electron excitation colour 45
Further Reading 46
Problems and Exercises 48
2 Colour Due to Refraction and Dispersion 51
2.1 Refraction and the Refractive Index of a Material 51
2.2 Total Internal Reflection 55
2.2.1 Refraction at an interface 55
2.2.2 Evanescent waves 56
2.3 Refractive Index and Polarisability 58
2.4 Refractive Index and Density 61
2.5 Invisible Animals, GRINS, and Mirages 63
2.6 Dispersion and Colours Produced by Dispersion 65
2.7 Rainbows 68
2.8 Halos 74
2.9 Fibre Optics 74
2.9.1 Optical communications 74
2.9.2 Optical fibres 75
2.9.3 Attenuation in glass fibres 77
2.9.4 Chemical impurities 78
2.9.5 Dispersion and optical fibre design 80
2.10 Metamaterials and Negative Refractive Index 83
2.10.1 Metamaterials 83
2.10.2 Hyperlenses 84
2.10.3 Invisibility cloaks 87
2.10.4 Metasurfaces and flat lenses 88
2.11 The Electro-Optic Effect and Photorefractive Materials 88
Further Reading 90
Problems and Exercises 92
3 The Production of Colour by Reflection 95
3.1 Reflection from a Single Surface 96
3.1.1 Reflection from a transparent plate 96
3.1.2 Data storage using reflection 97
3.2 Reflection from a Single Thin Film in Air 98
3.2.1 Reflection perpendicular to the film 98
3.2.2 Variation with viewing angle 101
3.2.3 Transmitted beams 102
3.3 The Colour of a Single Thin Film in Air 103
3.4 The Reflectivity of a Single Thin Film in Air 105
3.5 The Colour of a Single Thin Film on a Substrate 106
3.6 The Reflectivity of a Single Thin Film on a Substrate 107
3.7 Low-Reflection and High-Reflection Films 108
3.7.1 Antireflection coatings 108
3.7.2 Antireflection layers 109
3.7.3 Graded index antireflection coatings 111
3.7.4 High reflectivity surfaces 113
3.7.5 Interference modulated (IMOD) displays 113
3.8 Multiple Thin Films 114
3.8.1 Dielectric mirrors 114
3.8.2 Multilayer stacks 116
3.8.3 Interference filters and distributed Bragg reflectors 117
3.9 Fibre Bragg Gratings 118
3.10 ‘Smart’ Windows 120
3.10.1 Low-emissivity windows 121
3.10.2 Self-cleaning windows 122
3.11 Thin-Film Colours in Nature 123
3.11.1 Single thin-film reflection 123
3.11.2 Multilayer mirrors 124
3.11.3 Multilayer colour generation 125
3.11.4 Multilayer reflectors in blue butterflies 127
Further Reading 128
Problems and Exercises 129
4 Polarised Light and Crystals 135
4.1 Polarisation of Light 135
4.2 Polarised Light and Vision 137
4.3 Polarisation by Reflection 138
4.4 Polars 141
4.5 Crystal Symmetry and Refractive Index 143
4.6 Double Refraction: Calcite as an Example 144
4.6.1 Double refraction 144
4.6.2 Refractive index and crystal structure 147
4.7 The Description of Double Refraction Effects 148
4.7.1 Uniaxial crystals 148
4.7.2 Biaxial crystals 150
4.8 Colour Produced by Polarisation and Birefringence 152
4.9 Dichroism, Trichroism, and Pleochroism 154
4.10 Nonlinear Effects 156
4.10.1 Nonlinear crystals 156
4.10.2 Second and third harmonic generation 158
4.10.3 Frequency mixing 160
4.10.4 Optical parametric amplifiers and oscillators 161
4.11 Frequency Matching and Phase Matching 162
4.12 More on Second Harmonic Generation 164
4.12.1 Polycrystalline solids and powders 164
4.12.2 Second harmonic generation in glass 165
4.12.3 Second harmonic and sum frequency generation by organic materials 166
4.12.4 Second harmonic generation at interfaces 166
4.12.5 Second harmonic microscopy 168
4.13 Optical Activity 168
4.13.1 The rotation of polarised light by molecules 168
4.13.2 The rotation of polarised light by crystals 170
4.13.3 Circular birefringence and dichroism 171
4.14 Liquid Crystals 172
4.14.1 Liquid crystal mesophases 172
4.14.2 Liquid crystal displays 174
Further Reading 177
Problems and Exercises 179
5 Colour Due to Scattering 183
5.1 Scattering and Extinction 183
5.2 Tyndall Blue and Rayleigh Scattering 186
5.3 Blue Skies, Red Sunsets 187
5.4 Scattering and Polarisation 190
5.5 Mie Scattering 192
5.6 Blue Eyes, Blue Feathers, and Blue Moons 195
5.7 Paints, Sunscreens, and Related Matters 197
5.8 Multiple Scattering 199
5.9 Gold Sols and Ruby Glass 199
5.10 The Lycurgus Cup and Other Stained Glass 201
Further Reading 204
Problems and Exercises 205
6 Colour Due to Diffraction 209
6.1 Diffraction and Scattering 209
6.2 Diffraction and Colour Production by a Slit 210
6.3 Diffraction and Colour Production by a Rectangular Aperture 212
6.4 Diffraction and Colour Production by a Circular Aperture 213
6.5 The Diffraction Limit of Optical Instruments 215
6.6 Colour Production by Linear Diffraction Gratings 216
6.7 Two-Dimensional Gratings 221
6.8 Estimation of the Wavelength of Light by Diffraction 223
6.9 Diffraction by Crystals and Crystal-Like Structures 224
6.9.1 Bragg’s law 224
6.9.2 Opals 226
6.10 Photonic Crystals 229
6.10.1 Artificial and inverse opal structures 229
6.10.2 Diffraction from cubic photonic crystals 232
6.10.3 The effective refractive index of cubic photonic crystals 232
6.10.4 Dynamical form of Bragg’s law 234
6.10.5 Photonic bandgaps 235
6.10.6 Photonic crystals in nature 236
6.10.7 Photonic crystal fibres 238
6.11 Diffraction from Disordered Gratings 239
6.11.1 Random specks and droplets 239
6.11.2 Halos, coronae, and glories 240
6.11.3 Colour from cholesteric liquid crystals 242
6.11.4 Natural helicoidal structures 246
6.11.5 Disordered two- and three-dimensional gratings 247
6.12 Diffraction by Sub-Wavelength Structures 248
6.12.1 Diffraction by moth-eye antireflection structures 249
6.12.2 The cornea of the eye 250
6.12.3 Some blue feathers 251
6.13 Holograms 252
6.13.1 Holograms and interference patterns 252
6.13.2 Transmission holograms 253
6.13.3 Reflection holograms 255
6.13.4 Rainbow holograms 256
6.13.5 Hologram recording media 259
6.13.6 Embossed holograms 261
6.14 Hologram Formation 262
6.14.1 Interference of two coherent light waves 262
6.14.2 Image formation 263
Further Reading 266
Problems and Exercises 268
7 Colour from Atoms and Ions 273
7.1 The Spectra of Atoms and Ions 273
7.2 The Spectrum of Hydrogen 276
7.3 Terms and Levels 278
7.4 Atomic Spectra and Chemical Analysis 280
7.5 Fraunhofer Lines and Stellar Spectra 282
7.6 Neon Signs and Plasma Displays 283
7.7 The Helium-Neon Laser 285
7.8 Sodium and Mercury Street Lights 287
7.9 Atomic and Optical Clocks 289
7.9.1 Clocks 289
7.9.2 Atomic clocks 290
7.9.3 The 133Cs atomic clock 291
7.9.4 Optical clocks 291
7.10 Transition-Metal Cation Colours: Overview 291
7.11 Crystal Field Splitting 292
7.11.1 d-orbital interactions 292
7.11.2 Term splitting 295
7.11.3 Energies 297
7.11.4 Selection rules 297
7.12 The Crystal Field Colours of Transition-Metal Ions 299
7.12.1 3d1, 3d4, 3d5, 3d6, and 3d9 cations 299
7.12.2 3d2, 3d3, 3d7, and 3d8 cations 301
7.12.3 Octahedral and tetrahedral coordination 304
7.12.4 Thermochromism, piezochromism, and crystal-field splitting 306
7.13 Crystal Field Colours in Minerals and Gemstones 306
7.13.1 The colour of ruby 306
7.13.2 Emerald, chrome alum, and alexandrite 309
7.13.3 Malachite, azurite, and turquoise 311
7.14 Colour as a Structural Probe 311
7.15 Transition-Metal-Ion Lasers 313
7.15.1 The ruby laser: a three-level laser 313
7.15.2 The titanium-sapphire laser 314
7.16 Colours from Lanthanoid Ions 315
7.16.1 Lanthanoid ion colours: general 315
7.16.2 The colour of Ce3+ and Eu2+ 316
7.16.3 f-f colours: Pr3+, Tm3+, Nd3+, and Dy3+ 319
7.17 The Neodymium (Nd3+) Solid State Laser: A Four-Level Laser 319
7.18 Optical Amplifiers 322
7.18.1 Amplification of optical fibre signals 322
7.18.2 Fibre lasers 323
7.19 Transition Metal, Lanthanoid, and Actinoid Pigments 324
Further Reading 326
Problems and Exercises 327
8 Colour from Molecules 331
8.1 The Energy Levels of Molecules 331
8.1.1 Electronic, vibrational, and rotational energy levels 331
8.1.2 Molecular orbitals 333
8.1.3 Molecular orbitals in large molecules 333
8.1.4 Origin of molecular colours 336
8.2 The Colours Arising in Some Inorganic Molecules 337
8.2.1 Halogens 337
8.2.2 Auroras 338
8.2.3 Candles and fireworks 338
8.3 The Colour of Water 339
8.4 Ultramarine Pigments and Related Colours 341
8.5 Organic Chromophores, Chromogens, and Auxochromes 344
8.6 Conjugated Bonds in Organic Molecules: Carotenoids 345
8.7 Nonlinear Conjugated Bonds Involving N Atoms: Pterins 348
8.8 Conjugated Bonds Circling Metal Atoms: Porphyrins and Phthalocyanines 353
8.8.1 Porphin 353
8.8.2 Chlorophylls 354
8.8.3 Haemoglobins and related molecules 356
8.8.4 Phthalocyanins 358
8.9 Naturally Occurring Colourants: Flavonoid Pigments 358
8.9.1 Flavone-related colours: yellows 358
8.9.2 Anthocyanin-related colours: reds and blues 360
8.9.3 The colour of red wine 364
8.10 Autumn Leaves 364
8.11 Some Dyes and Pigments 367
8.11.1 Indigo, Tyrian purple, and mauve 367
8.11.2 Tannins 369
8.11.3 Melanins 370
8.12 Charge Transfer Colours 372
8.12.1 Charge transfer processes 372
8.12.2 Cation-to-cation (intervalence) charge transfer 373
8.12.3 Anion-to-cation charge transfer 377
8.12.4 Iron-containing minerals 378
8.13 Colour-Change Sensors 379
8.13.1 The detection of metal ions 380
8.13.2 Indicators 380
8.13.3 Colorimetric sensor films and arrays 383
8.13.4 Markers 384
8.14 Dye Lasers 384
8.15 Photochromic Organic Molecules 388
8.16 Biological Cell Stains 389
Further Reading 391
Problems and Exercises 393
9 Luminescence 397
9.1 Photoluminescence: Activators, Sensitisers, and Fluorophores 397
9.2 Photonic Processes in Photoluminescence 399
9.2.1 Fluorescence 400
9.2.2 Phosphorescence 402
9.2.3 Thermally activated delayed fluorescence (TADF) 402
9.2.4 Anti-Stokes-shift luminescence 404
9.3 Atomic Processes in Photoluminescence 405
9.3.1 Quantum yield and reaction rates 405
9.3.2 Structural interactions 407
9.3.3 Quenching 407
9.3.4 Ultralong organic phosphorescence (OLP) 412
9.3.5 Aggregation-induced fluorescence 413
9.4 Inorganic Luminescence 413
9.4.1 Fluorescent lamps 414
9.4.2 Halophosphate lamps 414
9.4.3 Trichromatic lamps 415
9.4.4 Other fluorescent lamps 417
9.5 Plasma Displays 418
9.6 Fluorescent Organic Molecules 419
9.6.1 Fluorescent molecular tags and proteins 420
9.6.2 Green fluorescent protein 421
9.6.3 Other fluorescent proteins 421
9.6.4 Photoactivatable fluorescent proteins (PA-FPs) 424
9.6.5 The mechanism of photoswitching 424
9.6.6 Synthetic fluorescent dyes 425
9.7 Microscopy 427
9.7.1 Fluorescence microscopy 427
9.7.2 Multiphoton excitation microscopy 428
9.7.3 Super-resolution imaging 429
9.8 Upconversion 434
9.8.1 Upconversion via lanthanoid cations 434
9.8.2 Ground state absorption and excited state absorption 435
9.8.3 Energy transfer 437
9.8.4 Other lanthanoid upconversion processes 439
9.8.5 Organic molecule sensitisers 440
9.8.6 Triplet-triplet annihilation 441
9.9 Quantum Cutting (Downconversion) 444
9.10 Fluorescent Markers and Sensors 445
9.11 Long-Lifetime Emission 447
9.11.1 Persistent luminescence 447
9.11.2 Photostimulable luminescence 450
9.11.3 Radiophotoluminescence 451
9.11.4 Optically stimulated luminescence in thermochronometry 451
9.11.5 Thermoluminescence 452
9.12 Scintillators 453
9.13 Chemiluminescent Light Emission 454
9.13.1 Chemiluminescence 454
9.13.2 Bioluminescence 455
9.13.3 Electrochemiluminescence 458
9.14 Mechanoluminescence and Related Light Emission 462
9.14.1 Triboluminescence 462
9.14.2 Sonoluminescence 463
9.15 Phosphor Electroluminescent Displays 463
9.16 Organic Molecule Electroluminescence and OLEDs 467
9.16.1 Molecular electroluminescence 467
9.16.2 Early OLED development 470
9.16.3 Later developments 472
9.16.4 White OLEDs and lighting 474
Further Reading 475
Problems and Exercises 476
10 Colour in Insulators, Semiconductors, and Metals 481
10.1 The Colours of Insulators 482
10.2 Excitons 484
10.3 Impurity Colours in Insulators 485
10.4 Colour Centres 486
10.4.1 The F Centre 487
10.4.2 Electron-Excess and Hole-Excess Centres 489
10.4.3 Impurity Colours in Diamond 491
10.4.4 Surface Colour Centres 494
10.4.5 Complex Colour Centres: Laser Action 495
10.4.6 Tenebrescence 496
10.5 The Colours of Inorganic Semiconductors 496
10.5.1 Coloured Semiconductors 496
10.5.2 Transparent Conducting Oxides 498
10.6 The Colours of Semiconductor Alloys 499
10.7 Light-Emitting Diodes (LEDs) 501
10.7.1 Direct and Indirect Bandgaps 501
10.7.2 Idealised Diode Structure 501
10.7.3 High Brightness LEDs 503
10.7.4 Impurity Doping in LEDs 504
10.7.5 LED Displays and White Light Generation 505
10.7.6 Perovskite LEDs 506
10.8 Semiconductor Diode Lasers 507
10.9 Semiconductor Nanostructures 508
10.9.1 Nanostructures 508
10.9.2 Quantum Wells 509
10.9.3 Two-Dimensional Light-Emitting Layered Structures 512
10.9.4 Quantum Wires and Rods 514
10.9.5 Quantum Dots 514
10.9.6 QLEDs 517
10.10 Electrochromic Films 517
10.10.1 Tungsten Trioxide Electrochromic Films 518
10.10.2 Inorganic Electrochromic Materials 521
10.10.3 Electrochromic Polymers 522
10.11 Photovoltaics 524
10.11.1 Photovoltaics and Photoconductivity 524
10.11.2 Photodiodes and Solar Cells 525
10.11.3 Dye-Sensitised Solar Cells 526
10.11.4 Perovskite Solar Cells 528
10.12 Digital Photography 530
10.12.1 Charge Coupled Devices (CCDs) 530
10.12.2 CCD Imaging 531
10.13 The Colours of Metals 532
10.13.1 Metallic Materials 532
10.13.2 Reflectivity of Metals 533
10.13.3 Reflectivity and Free Electron Theory 533
10.13.4 The Colour of Copper, Silver, and Gold 535
10.14 The Colours of Metal Nanoparticles 536
10.14.1 Surface Plasmons and Polaritons 536
10.14.2 Polychromic Glass 538
10.14.3 Photochromic Glass 539
10.14.4 Metal Nanoparticle Sensors and SERS 541
10.15 Extraordinary Light Transmission and Plasmonic Crystals 542
Further Reading 542
Problems and Exercises 543
Appendix A Definitions, Units, and Conversion Factors 549
A.1 Constants, Energy, and Conversion Factors 549
A.2 Waves 550
A.3 SI Units Associated with Radiation and Light 552
Appendix B The Colour of a Thin Film in White Light 555
Appendix C Hologram Formation 557
C.1 Interference of Two Coherent Light Waves 557
C.2 Image Formation 559
C.3 Wave Overlap and Interference 560
Appendix D Atomic Electron Configurations and Energy Levels 563
D.1 Electron Configurations of the Lighter Atoms 563
D.2 The 3d Transition Metals 564
D.3 The Lanthanoid Elements 565
D.4 The Vector Model of the Atom 566
D.5 Energy Levels and Terms of Many Electron Atoms 567
D.6 The Ground State Term of an Atom 569
D.7 Energy Levels of Many Electron Atoms 569
Index 571
