Subwavelength and Nanometer Diameter Optical Fibers (eBook)

While the author was at Harvard University, the pioneer work done by him and his colleagues in subwavelength and nanometer diameter optical fibers was reported on by leading magazines and newspapers such as Nature and the New York Times. The author has also been working on the fabrication, characterization and applications of crystal and glass optical fibers for more than 15 years. Research areas of the author include fundamentals of nanophotonics, optical nanostructures, optical fibers, and micro- and nanophotonic devices.

Title Page 3
Copyright Page 4
Preface 5
Table of Contents 7
1 Introduction 10
1.1 A Brief History of Micro- and Nanofibers 10
1.2 Concepts of MNFs and the Scope of this Book 12
References 16
2 Optical Waveguiding Properties of MNFs: Theory and Numerical Simulations 24
2.1 Basic Guiding Properties of Ideal MNFs 24
2.1.1 Mathematic Model 24
2.1.2 Single-mode Condition and Fundamental Modes 26
2.1.3 Fractional Power Inside the Core and Effective Diameter 31
2.1.4 Group Velocity and Waveguide Dispersion 34
2.2 Theory of MNFs with Microscopic Nonuniformities 37
2.2.1 Basic Equations 37
2.2.2 Conventional and Adiabatic Perturbation Theory 40
2.2.3 Transmission Loss Caused by a Weak and Smooth Nonuniformity 41
2.3 Theory of MNF Tapers 42
2.3.1 Semiclassical Solution of the Wave Equation in the Adiabatic Approximation and Expression of Radiation Loss 43
2.3.2 Optics of Light Propagation Along the Adiabatic MNF Tapers 44
2.3.3 Example of a Conical MNF Taper 45
2.3.4 Example of a Biconical MNF Taper 47
2.3.5 Example of an MNF Taper with Distributed Radiation Loss 49
2.4 The Thinnest MNF Optical Waveguide 51
2.5 Evanescent Coupling between Parallel MNFs: 3D-FDTD Simulation 52
2.5.1 Model for FDTD Simulation 53
2.5.2 Evanescent Coupling between two Identical Silica MNFs 54
2.5.3 Evanescent Coupling between two Silica MNFs with Different Diameters 59
2.5.4 Evanescent Coupling between a Silica MNF and a Tellurite MNF 60
2.6 Endface Output Patterns 62
2.6.1 MNFs with Flat Endfaces 63
2.6.2 MNFs with Angled Endfaces 66
2.6.3 MNFs with Spherical and Tapered Endfaces 68
2.7 MNF Interferometers and Resonators 69
2.7.1 MNF Mach-Zehnder and Sagnac Interferometers 69
2.7.2 MNF Loop Resonators 69
2.7.3 MNF Coil Resonators 73
References 78
3 Fabrication of MNFs 82
3.1 Taper Drawing Techniques 83
3.2 Taper-drawing Fabrication of Glass MNFs 86
3.2.1 Taper Grawing MNFs Rom Glass Fibers 87
3.2.2 Drawing MNFs Directly from Bulk Glasses 98
3.3 Drawing Polymer MNFs from Solutions 100
References 103
4 Properties of MNFs: Experimental Investigations 107
4.1 Micro/Nanomanipulation and Mechanical Properties of MNFs 107
4.1.1 Visibility of MNFs 108
4.1.2 MNF Manipulation 109
4.1.3 Tensile Strengths of MNFs 115
4.2 Optical Properties 117
4.2.1 Optical Losses 117
4.2.2 Effect of the Substrate 127
References 130
5 MNF-based Photonic Components and Devices 133
5.1 Linear Waveguides and Waveguide Bends 134
5.1.1 Linear Waveguides 134
5.1.2 Waveguide Bends 141
5.2 Micro-couplers, Mach-Zehnder and Sagnac Interferometers 143
5.2.1 Micro-couplers 143
5.2.2 Mach-Zehnder Interferometers 146
5.2.3 Sagnac Interferometers 149
5.3 MNF Loop and Coil Resonators 150
5.3.1 MNF Loop Resonator (MLR) Fabricated by Macro-Manipulation 150
5.3.2 Knot MLR Fabricated by Micro-Manipulation 154
5.3.3 Experimental Demonstration of MCR 155
5.4 MNF Filters 159
5.4.1 Short-Pass Filters 159
5.4.2 Add-Drop Filters 162
5.5 MNF Lasers 165
5.5.1 Modeling MNF Ring Lasers 167
5.5.2 Numerical Simulation of Er3+ and Yb3+ Doped MNF Ring Lasers 173
5.5.3 Er3+ and Yb3+ Codoped MNF Ring Lasers 178
5.5.4 Evanescent-Wave-Coupled MNF Dye Lasers 182
References 186
6 Micro/nanofiber Optical Sensors 194
6.1 Introduction 194
6.2 Application of a Straight MNF for Sensing 196
6.2.1 Microfluidic Refractive Index MNF Sensor 197
6.2.2 Hydrogen MNF Sensor 197
6.2.3 Molecular Absorption MNF Sensor 199
6.2.4 Humidity and Gas Polymer MNF Sensor 200
6.2.5 Optical Fiber Surface MNF Sensor 203
6.2.6 Atomic Fluorescence MNF Sensor 203
6.3 Application of Looped and Coiled MNF for Sensing 205
6.3.1 Ultra-Fast Direct Contact Gas Temperature Sensor 207
6.3.2 MCR Microfluidic Sensor 209
6.4 Resonant Photonic Sensors Using MNFs for Input and Output Connections 209
6.4.1 MNF/Microsphere and MNF/Microdisk Sensor 210
6.4.2 MNF/Microcylinder and MNF/Microcapillary Sensors . 215
6.4.3 Multiple-Cavity Sensors Supported by MNFs 217
6.5 Summary 219
References 219
7 More Applications 222
7.1 Optical Nonlinear Effects in MNFs 222
7.2 MNFs for Atom Optics 226
7.3 Other Applications 229
References 229
Index 232