1 Basic Concepts and the Discovery of Solitons 1
1.1 A look at linear and nonlinear signatures 1
1.2 Discovery of the solitary wave 3
1.3 Discovery of the soliton 6
1.4 The soliton concept in physics 10
2 Linear Waves in Electrical Transmission Lines 12
2.1 Linear nondispersive waves 12
2.2 Sinusoidal-wave characteristics 15
2.2.1 Wave energy density and power 18
2.3 The group-velocity concept 19
2.4 Linear dispersive waves 21
2.4.1 Dispersive transmission lines 21
2.4.2 Electrical network 23
2.4.3 The weakly dispersive limit 26
2.5 Evolution of a wavepacket envelope 27
2.6 Dispersion-induced wavepacket broadening 31
Appendix 2A.General solution for the envelope evolution 34
Appendix 2B. Evolution of the envelope of a Gaussian wavepacket 35
3 Solitons in Nonlinear Transmission Lines 37
3.1 Nonlinear and dispersionless transmission lines 37
3.2 Combined effects of dispersion and nonlinearity 41
3.3 Electrical solitary waves and pulse solitons 42
3.4 Laboratory experiments on pulse solitons 46
3.4.1 Experimental arrangement 46
3.4.2 Series of experiments 48
3.5 Experiments with a pocket version of the electrical network 52
3.6 Nonlinear transmission lines in the microwave range 56
Appendix 3A.Calculation of the effect of nonlinearity on wave propagation 58
Appendix 3B.Derivation of the solitary-wave solution 60
Appendix 3C.Derivation of the KdV equation and its soliton solution 62
Appendix 3D.Details of the electronics:switch driver and pulse generator 64
4 More on Transmission-Line Solitons 65
4.1 Lattice solitons in the electrical Toda network 65
4.1.1 Lattice solitons 67
4.2 Experiments on lattice solitons 68
4.2.1 Collisions of two lattice solitons moving in opposite directions 70
4.2.2 The Fermi-Pasta-Ulam recurTence phenomenon 70
4.3 Periodic wavetrains in transmission lines 71
4.3.1 The solitary wave limit and sinusoidal limit of the cnoidal wave 72
4.4 Modulated waves and the nonlinear dispersion relation 72
4.5 Envelope and hole solitons 74
4.5.1 Experiments on envelope and hole solitons 76
4.6 Modulational instability 77
4.7 Laboratory experiments on modulational instability 82
4.7.1 Model equations 82
4.7.2 Experiments 84
4.8 Modulational instability of two coupled waves 86
Appendix 4A.Periodic wavetrain solutions 88
Appendix 4B.The Jacobi elliptic functions 90
4B.1 Asymptotic limits 91
4B.2 Derivatives and integrals 93
Appendix 4C.Envelope and hole soliton solutions 93
5 Hydrodynamic Solitons 98
5.1 Equations for surface water waves 98
5.1.1 Reduced fluid equations 99
5.2 Small-amplitude surface gravity waves 100
5.3 Linear shallow-and deep-water waves 103
5.3.1 Shallow-waterwaves 103
5.3.2 Deep-water waves 104
5.4 Surface-tension effects:capillary waves 105
5.5 Solitons in shallow water 107
5.6 Experiments on solitons in shallow water 110
5.6.1 Experimental arrangement 111
5.6.2 Experiments 111
5.7 Stokes waves and soliton wavepackets in deep water 115
5.7.1 Stokes waves 115
5.7.2 Soliton wavepackets 116
5.7.3 Experiments on solitons in deep water 117
5.8 Experiments on modulational instability in deep water 118
Appendix 5A.Basic equations of fluid mechanics 121
5A.1 Conservation of mass 121
5A.2 Conservation of momentum 123
5A.3 Conservation of entropy 124
Appendix 5B.Basic definitions and approximations 124
5B.1 Streamline 124
5B.2 Irrotational and incompressible flow 125
5B.3 Two-dimensional flow:the stream function 126
5B.4 Boundary conditions 128
5B.5 Surface tension 129
Appendix 5C.Derivation of the KdV equation:the perturbative approach 130
Appendix 5D.Derivation of the nonlinear dispersion relation 133
Appendix 5E.Details of the probes and the electronics 136
6 Mechanical Solitons 137
6.1 An experimental mechanical transmisssion line 137
6.1.1 General description of the line 137
6.1.2 Construction of the line 139
6.2 Mechanical kink solitons 139
6.2.1 Linear waves in the low-amplitude limit 140
6.2.2 Large amplitude waves:kink solitons 141
6.2.3 Lorentz contraction of the kink solitons 143
6.3 Particle properties of the kink solitons 145
6.4 Kink-kink and kink-antikink collisions 146
6.5 Breather solitons 148
6.6 Experiments on kinks and breathers 150
6.7 Helical waves,or kink array 151
6.8 Dissipative effects 153
6.9 Envelope solitons 155
6.10 Pocket version of the pendulum chain,lattice effects 157
Appendix 6A.Kink soliton and antikink soliton solutions 159
Appendix 6B.Calculation of the energy and the mass of a kink soliton 160
Appendix 6C.Solutions for kink-kink and kink-antikink collisions,and breathers 161
6C.1 Kink solutions 163
6C.2 Kink-kink collisions 163
6C.3 Breather solitons 164
6C.4 Kink-antikink collision 165
Appendix 6D.Solutions for helical waves 166
7 Fluxons in Josephson Transmission Lines 168
7.1 The Josephson effect in a short junction 168
7.1.1 The small Josephson junction 169
7.2 The long Josephson junction as a transmission line 171
7.3 Dissipative effects 175
7.4 Experimental observations of fluxons 177
7.4.1 Indirect observation 177
7.4.2 Direct observation 178
7.4.3 Latrice effects 180
Appendix 7A．Josephson equations 180
8 Solitons in Optical Fibers 182
8.1 Optical-fiber characteristics 182
8.1.1 Linear dispersive effects 183
8.1.2 Nonlinear effects 185
8.1.3 Effect of losses 186
8.2 Wave-envelope propagation 187
8.3 Bright and dark solitons 189
8.3.1 Bright solitons 190
8.3.2 Dark solitons 192
8.4 Experiments on optical solitons 193
8.5 Perturbations and soliton communications 195
8.5.1 Effect of losses 195
8.5.2 Soliton communications 196
8.6 Modulational instability of coupled waves 197
8.7 A look at quantum optical solitons 198
Appendix 8A.Electromagnetic equations in a nonlinear medium 199
9 The Soliton Concept in Lattice Dynamics 202
9.1 The one-dimensional lattice in the continuum approximation 202
9.2 The quasi-continuum approximation for the monatomic lattice 207
9.3 The Toda lattice 209
9.4 Envelope solitons and localized modes 210
9.5 The one-dimensional lattice with transverse nonlinear modes 212
9.6 Motion of dislocations in a one-dimensional crystal 215
9.7 The one-dimensional lattice model for structural phase transitions 216
9.7.1 The order-disorder transition 218
9.7.2 The displacive transition 219
Appendix 9A.Solutions for transverse displacements 221
Appendix 9B.Kink soliton or domain-wall solutions 223
10 A Look at Some Remarkable Mathematical Techniques 225
10.1 Lax equations and the inverse scattering transform method 225
10.1.1 The Fourier-transform method for linear equations 226
10.1.2 The Lax pair for nonlinear evolution equations 227
10.2 The KdV equation and the spectral problem 229
10.3 Time evolution of the scattering data 230
10.3.1 Discrete eigenvalues 230
10.3.2 Continuous spectrum 232
10.4 The inverse scattering problem 233
10.4.1 Discrete spectrum only:soliton solution 234
10.5 Response of the KdV model to an initial disturbance 236
10.5.1 The delta function potential 236
10.5.2 The rectangular potential well 237
10.5.3 The sech-squared potential well 237
10.6 The inverse scattering transform for the NLS equation 238
10.7 The Hirota method for the KdV equation 239
10.8 The Hirota method for the NLS equation 243
References 247
Subject Index 259