Laser Processing of Materials (eBook)

Preface 6
Contents 8
Contributors 14
Chapter 1: Introduction 16
References 18
Chapter 2: Basics of Lasers and Laser Optics 19
2.1 Introduction 19
2.2 Optical Processes 19
2.3 Time Dependence 22
2.3.1 Q-Switching 22
2.3.2 Mode-Locking 23
2.3.3 Ultrashort Pulse Generation 23
2.3.4 Harmonic Generation 23
2.4 Free-Electron Lasers 24
2.5 Laser Optics 26
2.5.1 Optical Propagation 27
2.5.2 Sizing Optical Elements and Other Tricks of the Trade 28
2.5.3 Fiber Optics 28
2.5.4 Managing Diffraction 29
2.5.5 The Aspheric Lens Beamshaper 29
2.5.6 Holographic Optical Elements 30
2.5.7 Laser Damage 31
2.5.8 Optical Modeling Software 33
2.6 Conclusions 33
References 33
Chapter 3: Fundamentals of Laser-Material Interactions 35
3.1 Basic Considerations 35
3.2 Laser 36
3.3 Heat in Solids: Electronic and Lattice Dynamics 37
3.4 Laser-Material Interactions 41
3.4.1 Single Photon and Multi-Photon Processes 41
3.4.2 Laser Reflection and Absorption 42
3.4.3 Temperature Profiles 45
3.5 Phenomena Occurring on the Target Surface 49
3.5.1 Vaporization 49
3.5.2 Recondensation 50
3.5.3 Plasma Formation 51
3.5.4 Laser Supported Absorption Waves 53
3.6 Material Transport Phenomena 56
3.7 Conclusions 58
References 58
Chapter 4: Laser–Plasma Interactions 62
4.1 Introduction 62
4.2 Fundamentals of Laser–Plasma Interaction 63
4.3 Processes in Nanosecond Laser–Plasma Interactions 68
4.3.1 Laser-Induced Gas Breakdown 68
4.3.2 Plasma Shielding During Laser Material Processing 72
4.3.2.1 Target Vaporization 72
4.3.2.2 Plasma Ignition in the Vapor 73
4.3.2.3 Plasma Ignition in the Ambient Gas 74
4.3.2.4 The Role of Surface Defects 74
4.3.3 Laser-Supported Absorption Waves 76
4.3.3.1 Definition and Modeling 76
4.3.3.2 Propagation Modes 78
4.3.4 Plasma Shutter for Optical Limitation 79
4.3.4.1 Mechanisms and Characteristic Times 79
4.3.4.2 Plasma Shutter Applications 81
4.4 Plasma Interactions with Femtosecond Laser Pulses 82
4.4.1 Laser Beam Filamentation 82
4.4.1.1 Mechanisms and Processes 82
4.4.1.2 Applications of Laser Beam Filamentation 85
4.4.2 Generation of XUV Radiation by Laser Plasma 88
4.4.2.1 Pulsed XUV Radiation Sources: A Review 88
4.4.2.2 Laser Plasma X-Ray Sources 90
4.4.2.3 High-Order Harmonic Generation 90
4.4.3 Plasma Mirror 93
4.4.3.1 Short Laser Pulse ``cleaning' by Plasma Mirrors 93
4.4.3.2 Harmonic Generation by Plasma Mirror 95
4.5 Conclusion 96
References 97
Chapter 5: Laser Ablation and Thin Film Deposition 102
5.1 Pulsed Laser Ablation 102
5.2 Lasers Used for Laser Ablation 104
5.3 Initial Ablation Processes and Plume Formation 105
5.3.1 Femtosecond Laser Irradiation 106
5.3.2 Nanosecond Laser Irradiation 106
5.4 Plume Expansion 107
5.4.1 Plume Expansion in Vacuum 107
5.4.2 Plume Expansion into a Background Gas 107
5.4.3 Imaging 108
5.4.4 Kinetic Energy of Plume Species 110
5.4.5 Thin Film Growth 111
5.5 Laser Ablation of Polymers 117
5.5.1 Ablation Mechanism 118
5.5.2 Polymer Film Ablation 119
5.5.3 Film Pattern Transfer 120
5.6 Conclusions 122
References 122
Chapter 6: Processing with Ultrashort Laser Pulses 126
6.1 Introduction and General Considerations 126
6.2 Laser-Material Coupling 127
6.2.1 Nonlinear Absorption 128
6.2.2 Hot Electron Generation 129
6.2.3 Incubation 129
6.2.4 Resolution Below the Diffraction Limit 130
6.3 Dissipation Dynamics 131
6.3.1 Dissipation Channels 131
6.3.2 Transient Material Modification 131
6.4 Desorption/Ablation 133
6.4.1 Concept 133
6.4.2 Applications 133
6.5 3-D Bulk Modifications, Waveguide Writing 135
6.5.1 Bulk Structuring, Waveguide Writing 136
6.5.2 Multiphoton Polymerization 136
6.6 Phase Transformation, Laser Annealing 137
6.7 Medical Applications 137
6.8 Nanostructures and Nanoparticles 137
6.9 Conclusions 139
References 139
Chapter 7: Creating Nanostructures with Lasers 143
7.1 Introduction 144
7.2 Fundamentals 145
7.2.1 Plasma–Gas Interaction at Increasing Gas Pressure in ns PLD: Experiments and Modeling 145
7.2.2 Nanoparticle Synthesis 152
7.2.3 Controlled Deposition of 2D Nanoparticle Arrays: Self-Organization, Surface Topography, and Optical Properties 155
7.3 NP Formation in Femtosecond PLD: Experimental Results and Mechanisms 158
7.4 Applications 163
7.4.1 Direct Writing 164
7.4.2 Laser LIGA 164
7.4.3 Laser Etching 165
7.4.4 Pulsed Laser Deposition 166
7.4.5 Matrix-Assisted Pulsed Laser Evaporation (MAPLE) 172
7.4.6 Laser-Assisted Chemical Vapor Deposition (LA-CVD) 173
7.4.7 Lasers for MEMS (Micro-Electro-Mechanical Systems) 175
7.5 Concluding Remarks 175
References 177
Chapter 8: Laser Micromachining 180
8.1 Basic Considerations 180
8.2 Processing Limits 180
8.3 Materials and Processes 182
8.3.1 Polymers 182
8.3.2 Glass 184
8.3.3 Ceramics 184
8.3.4 Metals 185
8.3.5 Layer Ablation 186
8.3.6 Indirect Ablation 187
8.4 Hole Drilling 189
8.5 Patterning of Thin Films 190
8.5.1 Dielectric Masks 190
8.5.2 Diffractive Optical Elements 191
8.6 Fabrication of Micro Optics and Micro Fluidics 192
8.6.1 Gratings 192
8.6.2 Micro Lenses 193
8.6.3 Micro Fluidics 194
8.7 Conclusions 195
References 196
Chapter 9: Laser Processing Architecture for Improved Material Processing 199
9.1 Laser Machining and Materials Processing 200
9.1.1 Introduction 200
9.1.2 Materials, Thermodynamic Properties, and Light/Matter Interaction 202
9.1.3 Photolytic Control: Conventional Approaches and Future Trends 203
9.1.4 Process Control 204
9.2 Laser Genotype Pulse Modulation Technique 206
9.2.1 Concept 206
9.2.2 Experimental Setup and Design 208
9.2.3 Performance Tests and Diagnostics 214
9.2.3.1 PSO Functionality 214
9.2.3.2 Velocity Compensation via PSO Control 218
9.2.3.3 Site-Selective Pulse Script Variation 219
9.3 Selected Applications 221
9.3.1 Photosensitive Glass Ceramics: A Candidate Protean Material Class 221
9.3.1.1 Modification of Optical Properties 221
9.3.1.2 Silicate Phase Fractionation 222
9.3.2 Nanostructured Perovskite Thin-Films 225
9.3.2.1 Conventional Laser Direct-Write Processing 226
9.3.2.2 Genotype-Inspired, Digitally Scripted Laser Direct-WriteProcessing 227
9.4 Summary and Perspective 229
9.4.1 Laser Genotype Process Integration 229
9.4.2 Pulse Script Database: A Public Domain Catalogfor Materials Processing 231
References 232
Index 235