Photonic Packaging Sourcebook (eBook)

Prof. Dr. rer .nat. Dr.-Ing. habil Ulrich Fischer-Hirchert is CEO of HarzOptics GmbH, Wernigerode, and Professor of Communication Technics at the Harz University of Applied Sciences, Wernigerode.

Preface 5
Contents 7
Abbreviations 13
1 Introduction into Photonic Packaging 20
Abstract 20
1.1 Optical Transmission Systems 20
1.2 System Applications of Optical Communications 23
1.2.1 Optical Telecommunication Systems 23
1.2.2 Optical Datacom Systems 27
1.2.3 Optical Systems in Cars and In-house Areas 30
1.3 Photonic Packaging and Interconnection Technology 34
References 37
2 Optical Waveguides 41
Abstract 41
2.1 The Most Important Optical Laws 41
2.1.1 Homogeneous Plane Wave 42
2.1.2 Phase and Group Velocity 44
2.1.3 Reflection 44
2.1.4 Refraction 45
2.1.5 Total Reflection 46
2.1.6 Numerical Aperture 47
2.2 Optical Fiber Profiles 47
2.2.1 Step Profile 49
2.2.2 Monomode Glass Fibers 51
2.2.3 Gradient profile 53
2.2.4 Phase-space Diagrams: ({{/bf sin}^{/bf 2} {/Theta} /,{/bi and}/,{/bi r}^{/bf 2} } ) 54
2.3 Dispersion 55
2.4 Attenuation 56
2.5 Polymeric Fibers 58
2.6 Optical Waveguides in InP, GaAs, PMMA, and SiO2 59
2.6.1 Geometry of Integrated Waveguides 61
2.6.2 Semiconductor Laser 62
2.6.3 PMMA-integrated Waveguides 63
2.7 SiO2-Optical Waveguides 65
2.8 Production of Optical Fibers 66
2.9 Gas Phase Methods 67
2.9.1 Drawing of Glass Fibers 70
2.9.2 Types of Fiber-Optic Cables 71
References 72
3 Optical Mode-field Adaptation 74
Abstract 74
3.1 Theory of Optical Mode-field Adaptation 75
3.2 Definition of Field Radius 75
3.3 Approximations to Determine the Mode-field Radius 81
3.4 Loss Mechanisms in the Waveguide Coupling 83
3.5 Coupling Efficiency in Case of Mode-field Mismatch 84
3.6 Coupling Efficiency in the Presence of Longitudinal Displacement 87
3.7 Coupling Efficiency in the Presence of Transverse Offset 89
3.8 Coupling Efficiency in the Presence of Angular Misalignment 90
References 92
4 Fiber-Optical Coupling 94
Abstract 94
4.1 Adjusting Techniques 94
4.1.1 Active Techniques 94
4.1.2 Passive Techniques 95
4.2 Fixation Techniques 97
4.3 Characteristics of a Good Coupling 98
4.4 Reflections 99
4.5 Mode Fields in Waveguide Structures (Spot Size) 100
4.6 Coupling Efficiencies 102
4.7 Laser--Fiber Coupling 108
4.8 Waveguide Taper 114
4.9 Mode-Field Measurement Methods 114
4.9.1 Near-Field Method 115
4.9.2 Median-Field Method 117
4.9.2.1 Automated Acquisition 120
4.9.2.2 Measurement Setup 121
4.9.2.3 Results 122
4.9.3 Far-Field Method 124
4.10 Summary 125
References 125
5 RF Lines 127
Abstract 127
5.1 Maxwell's Equations 127
5.2 Wave Types 129
5.3 Conduction Equations 131
5.4 Skin Effect 133
5.5 Coaxial Cables 134
5.6 Wave Impedance 136
5.7 Coplanar Lines 136
5.8 Substrate Materials 138
5.9 High-Frequency Connection of OEICs 140
5.9.1 K-plug Connection 141
5.9.2 RF Supply from the Plug to the OEIC 142
5.10 Production of Coplanar Lines 143
5.10.1 TMM Substrate 143
5.10.2 Alumina Ceramic 145
5.10.3 Silicon 146
References 147
6 Soldering, Adhesive Bonding, and Bonding 148
Abstract 148
6.1 Die Bonding 148
6.2 Heat Sinks 149
6.3 Failure Mechanisms 152
6.4 Reliability Tests 153
6.5 Adhesive Bonding 153
6.6 Wire Bonding 154
6.7 Thermo-compression Bonding 157
6.8 Ultrasonic Bonding 159
6.9 Thermo-sonic Bonding 160
6.10 Bonding Tools 160
References 162
7 Optical Connection Technology 163
Abstract 163
7.1 Single-Fiber Connectors 163
7.2 Multi-mode and Multi-fiber Connectors 165
7.3 Examples of Optical Connectors 166
7.4 Optical Fiber Tapers 171
7.4.1 Manufacturing of Fiber Tapers 171
7.4.2 Taper Measurement Setup 173
7.4.3 Measurement of the Reference Light Source 175
7.4.4 Measurement of the Reference Light Coupled to the Fiber 176
References 179
8 Active Adjustment Techniques 180
Abstract 180
8.1 Micrometer Positioners 180
8.1.1 Mechanical Positioners 180
8.2 Laser Microwelding 186
8.2.1 Laser Welding Methods 186
8.3 Criteria for the Choice of Welding Methods 187
8.4 Laser Material Processing 188
8.5 Industrial Multi-point Laser Welding 191
8.6 Laser Micro-welding for Modules with Tapered Fibers 193
8.6.1 Coupling Concept 193
8.6.2 Module Setup 196
8.6.3 Flange Setup 197
8.6.4 Welding Results 198
8.6.5 Initial Welding Results 199
8.6.6 Correction After Initial Welding 202
8.6.7 Dynamical Shift 204
References 205
9 Passive Adjustment Techniques 206
Abstract 206
9.1 Flip-Chip Technique 206
9.1.1 Flip-Chip Bonder 213
9.1.2 Reduction of the Oxide Layers During Bonding 215
9.1.3 Flip-Chip-Bonding of Optical Components 216
9.1.4 Metallization 217
9.1.5 Lithography 218
9.1.6 Coatings with Increased Layer Thickness 220
9.1.7 Solder Deposition 221
9.1.8 Bonding Process 222
9.2 LIGA Technique 224
9.3 Laser Structuring of Si and PMMA 226
References 228
10 Optical Motherboard 230
Abstract 230
10.1 Flip-Chip Technique 230
10.2 Three-Level Concept 232
10.2.1 First Level: FC-Bonding and Tapered Waveguide 232
10.2.2 Second Level: Silica Waveguides 234
10.2.3 Third Level: Addition of RF Lines and Electrical ICs 235
10.3 PCB-Level Photonic Integration 236
10.3.1 PCB-Level Integrated Waveguides 237
10.3.1.1 Optical Materials 238
10.3.1.2 Manufacturing Techniques for Optical Waveguides on PCB-Level 239
10.3.2 Photonic Packaging for Optoelectronic Devices 243
10.3.3 Optical Coupling for Board-Level Interconnects 245
References 248
11 Fiber Optic Modules 253
Abstract 253
11.1 Fiber--Chip Coupling Mechanisms in Module Construction 253
11.1.1 Butt Fiber Couplings 253
11.1.2 Single-mode Fiber Coupling 254
11.1.3 Fiber Taper Coupling 255
11.2 Transmitter Modules with Cooling 256
11.3 Dual Inline Package Modules 258
11.3.1 Module Setup 259
11.3.2 Laser Welding Results 260
11.3.3 RF Results 262
11.3.4 Environmental Tests 262
11.4 Receiver Modules 262
11.5 Transceiver Modules 268
11.6 Multi-fiber Modules with Butt-Ended Fibers 269
11.6.1 Device Characteristics 270
11.6.2 Optical Coupling Setup 270
11.6.3 Module Packaging 273
11.6.4 Environmental Stability 275
11.7 Multi-fiber Modules with Lensed Fibers 276
11.7.1 Coupling Concept 277
11.7.2 Module Setup 278
11.7.3 Coupling Procedure 279
References 280
12 From Chip Design to the Optimum Package 281
Abstract 281
12.1 General Requirements 281
12.2 Design Optimization with the Finite Element Method 282
12.3 Procedure of Finite Element Analysis and Software Packages 283
12.4 ANSYS Classic Introduction 287
12.4.1 Getting Help 287
12.4.2 Command Input 288
12.4.3 System of Units 288
12.4.4 ANSYS Selection Techniques 288
12.4.5 Working Plane 289
12.4.6 CAD Interfaces 289
12.4.7 ANSYS Files 289
12.5 Programming Example 290
12.5.1 Introduction 290
12.5.2 Procedure of the Sequential Thermal Stress Analysis 291
12.5.3 Element Types 293
12.5.3.1 ANSYS Element Compatibility 293
12.5.3.2 SOLID90--3D 20-Node Thermal Solid 294
12.5.3.3 SOLID95--3D 20-Node Structural Solid 294
12.5.4 ANSYS Command Listing 296
12.5.5 Programming Code Listing 297
12.6 Optical Simulation Programs 311
12.6.1 Mathematical Model of Ray Tracing Programs 312
12.6.2 Basic Conventions of Optical Simulation Software 314
12.6.3 Strengths and Weaknesses of Ray Tracing 315
12.7 Overview of Different Simulation Programs 317
12.7.1 Simulation Programs Based on Wave Optics 317
12.7.2 Beam Propagation Method 318
12.7.3 Finite-Difference Time-Domain Method 318
References 319
13 Reliability Tests 320
Abstract 320
13.1 Test Methods and Standards 320
13.2 Standards Reference Sources 322
13.3 Stability Criteria of Telcordia Technologies 324
13.3.1 Transmitter and Receiver Modules 324
13.3.2 Arrayed Waveguide Grating Modules 324
13.4 Shaker Test Stations 327
References 329
Index 330