Photonic Structures Inspired by Nature (eBook)

Photonic StructuresInspired by Nature 3
Supervisor’s Foreword 7
Acknowledgments 9
Contents 11
1 Introduction 14
References 16
2 Theoretical Aspects of Photonic Structures 17
2.1…Reflection and Refraction at Optical Interfaces 18
2.2…Thin Film Interference 19
2.3…Multilayer Reflectivity 21
2.3.1 Qualitative Analysis of Multilayer Interference 21
2.3.2 Quantitative Analysis of Multilayer Interference 22
2.3.2.1 Rouard’s Technique 22
2.3.2.2 Results 23
2.4…Band-Gaps of One-Dimensional Photonic Crystals 24
2.5…Multilayer Resonance Cavities 30
2.6…Diffraction from Periodic Surface Structures 33
2.6.1 Diffraction in the Fraunhofer Approximation 34
2.6.2 Finite-Difference Time-Domain Modelling of Diffraction 35
References 38
3 Structural Colours in Nature 40
3.1…Structural Colours in the Animal Kingdom 41
3.1.1 Simple Multilayers: The Japanese Jewel Beetle 41
3.1.2 Complex Multilayer Arrangements in Butterfly and Moth Structures 42
3.1.2.1 Enhanced Reflectivity in the Moth Chrysiridia rhipheus: Using Air as a Multilayer Material 43
3.1.2.2 Sculpted Multilayer Structures: Papilio palinurus and Papilio blumei 46
3.1.2.3 Fine-Structured ‘‘Christmas-Tree’’-Like Ridges on the Scales of Morpho rhetenor 48
3.2…Floral Diffractive Structures 50
3.2.1 Diffraction and Iridescence from Striations on Flower Petals 50
3.2.1.1 Optical Characterisation 51
3.2.1.2 Iridescence, a Cue for Pollinators 56
3.2.2 Near-UV Reflectivity Enhancement by Grating-Like Striations 60
3.3…Conclusion 63
References 64
4 Materials and Techniques 68
4.1…Materials 68
4.1.1 Polymer Materials 68
4.1.1.1 TeflonregAF 68
4.1.1.2 Polystyrene 69
4.1.1.3 Polystyrene Colloids 69
4.1.1.4 Polydimethylsiloxane 70
4.1.1.5 Polyisoprene--Polystyrene Triblock Copolymer 70
4.1.1.6 Dental Wax 70
4.1.1.7 Organic Dyes 71
4.1.2 Metal Oxides 72
4.1.2.1 Aluminium Oxide 72
4.1.2.2 Titanium(IV)oxide 72
4.2…Techniques: Multilayer Production 72
4.2.1 Sequential Spin-Coating 72
4.2.2 Floating and Stacking 73
4.2.3 Atomic Layer Deposition 74
4.3…Techniques: Pattern Creation and Transfer 77
4.3.1 Colloid Templating 77
4.3.2 Argon Ion Milling 78
4.3.3 Nano-Imprint Lithography 80
4.3.4 Dental Wax Casting 81
4.4…Techniques: Sample Characterisation 81
4.4.1 Gonio-Spectroscopy 82
4.4.2 Micro-Spectroscopy 84
4.4.3 Ellipsometry 85
References 86
5 Static and Tuneable One-Dimensional Photonic Structures 90
5.1…Static One-Dimensional Optical Devices 90
5.1.1 Organic Bragg Reflectors 91
5.1.2 Organic Resonance Cavities 95
5.2…Stretch-Tuneable Dielectric Mirrors and Optical Microcavities 98
5.2.1 Sample Preparation and Experimental Setup 99
5.2.1.1 ‘‘Cut and Stack’’ Technique 101
5.2.1.2 ‘‘Roll-Up’’ Technique 101
5.2.1.3 ‘‘Origami’’ Technique 101
5.2.2 Cavity Design and Modelling 102
5.2.3 Results and Discussions 103
5.3…Conclusion 107
References 108
6 Microfabrication of Photonic Structures with Higher Dimensionality 110
6.1…Template-Assisted Ion Milling 111
6.1.1 The Ion Milling Template 111
6.1.2 Micro-Cones 111
6.1.3 Gold Crowns on Micro-Cones 113
6.1.4 Multilayer Patterning by Ion Milling 116
6.2…Nano-Imprinting of Photonic Structures 120
6.2.1 Imprinting with Micro-Cone Masters 120
6.2.2 Replication of Micro-Cones for Flexible Cell Substrates 122
6.2.3 Fabrication of an Imprint Master for the Replication of Butterfly Wing Scale Patterns 123
6.2.4 Multilayer Patterning by Nano-Imprinting 125
6.3…Atomic Layer Deposition on Structured Substrates 127
6.4…Conclusion 129
References 129
7 Mimicry of Papilio blumei’s Colourful Wing Scale Structure 132
7.1…The Role Model 132
7.2…The Replication Procedure 134
7.3…A Structural Replica 134
7.4…A Structurally Modified Replica with Enhanced Optical Performance 140
7.5…Conclusion 143
References 144
8 Conclusions and Future Work 145
8.1…Summary 145
8.2…Future Work 147
Curriculum Vitae 148
Scholarships and Awards: 149
Highest Ranking Publication: 149
Significant Conference Contributions: 149
Language Skills: 150
Activities and Responsibilities: 150
References: 150