| Preface | p. xv |
| Acknowledgments | p. xvii |
| Past, Present and Future | p. 1 |
| Introduction | p. 1 |
| History | p. 3 |
| Present Ongoing Efforts | p. 7 |
| Future Outlook | p. 8 |
| References | p. 8 |
| Architecture and Applications | p. 11 |
| Why Laser Communications? | p. 11 |
| Architecture | p. 12 |
| Satellite Orbits | p. 13 |
| Laser Communication Applications Overview | p. 18 |
| References | p. 22 |
| Systems Design Methodology | p. 23 |
| Generic System Design | p. 24 |
| End-To-End Link Design | p. 26 |
| Link Establishment | p. 26 |
| Link Maintenance | p. 29 |
| Data Transfer | p. 31 |
| Design Approaches | p. 32 |
| Coherent-Detection Systems | p. 33 |
| Direct-Detection Systems | p. 34 |
| Multiplexing Approaches | p. 35 |
| Design Trade Options | p. 36 |
| Laser Technology Base | p. 36 |
| Detector Technology Base | p. 39 |
| Isolation Technology | p. 46 |
| Beamsteering Technology | p. 48 |
| Acquisition | p. 51 |
| Pointing And Tracking | p. 70 |
| Communication Techniques | p. 82 |
| The Optical Link Equation | p. 94 |
| Transmit Source Power | p. 95 |
| Transmitter Optical Losses | p. 96 |
| Effective Transmit Gain | p. 96 |
| Range Loss | p. 103 |
| Receive Antenna Gain | p. 103 |
| Receiver Optical Losses | p. 103 |
| Receiver Pointing Loss | p. 104 |
| Received Signal Level | p. 104 |
| Required Signal Levels | p. 104 |
| Link Margin | p. 104 |
| Conclusion | p. 105 |
| References | p. 105 |
| Optical Design | p. 107 |
| Optical Crosslink System Overview | p. 107 |
| Pointing Elements | p. 108 |
| Gimbaled Flat | p. 108 |
| Gimbaled Telescope | p. 109 |
| Gimbaled Package | p. 111 |
| Laser Beams | p. 112 |
| Transmitted Wavefront Error | p. 113 |
| Transmitter Gaussian Amplitude Distribution | p. 114 |
| Strehl Ratio | p. 115 |
| Receive Spot Diameter | p. 115 |
| Transmitter Beam Divergence | p. 116 |
| Transmitter Gain | p. 116 |
| Receiver Gain | p. 117 |
| Telescopes | p. 118 |
| Telescope Types | p. 118 |
| Telescope Optical Characterization | p. 121 |
| Off-Axis Stray Light Rejection | p. 122 |
| Diffraction-Limited Telescopes | p. 125 |
| Telescope Materials | p. 125 |
| Telescope Weight | p. 128 |
| Photon Buckets | p. 128 |
| Imaging Optics | p. 129 |
| Signal Routing | p. 130 |
| Point-Ahead | p. 130 |
| Beam Shaping | p. 131 |
| Isolation | p. 131 |
| Power Monitoring | p. 133 |
| Transmitter Interfacing | p. 133 |
| Active Focus | p. 134 |
| Signal Routing | p. 134 |
| Filtering Out Stray Light | p. 134 |
| Receive Viewfield Splitting | p. 136 |
| Detector Interfacing | p. 136 |
| Field Stop Adjustment | p. 136 |
| Beamsteering | p. 137 |
| Boresight Alignment | p. 138 |
| Redundancy and Switching | p. 139 |
| Common Mounting Structure | p. 139 |
| Thermal Control | p. 139 |
| Budget Allocations/Interfaces | p. 140 |
| Alignment Budget | p. 140 |
| Wavefront Quality Budget | p. 140 |
| Transmission Budget | p. 141 |
| Interface Control | p. 142 |
| Weight Budget | p. 142 |
| The Use of Optical Design Programs | p. 143 |
| References | p. 143 |
| The Communication Receiver | p. 145 |
| The Direct-Detection Receive Process | p. 145 |
| Classical Direct Detection--No Optical Preamplification | p. 147 |
| Direct Detection With Optical Preamplification | p. 160 |
| The Coherent-Detection Process | p. 164 |
| LO Intensity Fluctuations | p. 165 |
| Mixing Efficiency | p. 165 |
| Phase and Frequency Noise | p. 166 |
| References | p. 167 |
| The Acquisition Receiver | p. 169 |
| Pulse Detection Acquisition Receivers | p. 169 |
| Noise in the Pulsed Acquisition Process | p. 170 |
| The Pulsed Acquisition Required Signal | p. 173 |
| Tone Acquisition Receivers | p. 174 |
| Tone Acquisition Receiver With Envelope Detection | p. 174 |
| Tone Acquisition Via Phase Locked Loop Techniques | p. 175 |
| Integrating Device Acquisition Receivers | p. 176 |
| Charge-Coupled Device Receivers | p. 176 |
| Charge-Injection Device Receivers | p. 177 |
| Required Signal for Integrating Device Receivers | p. 177 |
| Summary | p. 178 |
| References | p. 178 |
| The Tracking Receiver | p. 179 |
| Governing Requirements | p. 179 |
| Required Signal Development | p. 180 |
| Conventional Quadrant Devices | p. 180 |
| Integrating Devices | p. 184 |
| Required Signal Development (Coherent Tracking) | p. 189 |
| Slope Factor Determination | p. 189 |
| Transition Region Types | p. 191 |
| Slope Factor | p. 192 |
| Summary | p. 194 |
| References | p. 195 |
| Key Technologies | p. 197 |
| Optomechanical Technologies | p. 197 |
| Pointing Element Gimbals | p. 197 |
| Beamsteerers | p. 219 |
| Mechanisms | p. 222 |
| Optical Mounts | p. 224 |
| Laser Technology | p. 228 |
| Required Characteristics for Space Lasers | p. 228 |
| Types of Lasers/Trades | p. 229 |
| Detector Technology | p. 243 |
| Photoconductive Detector Devices | p. 243 |
| Integrating Imaging Devices | p. 248 |
| Utility Detector Devices | p. 249 |
| Summary | p. 250 |
| References | p. 250 |
| Configuring the System | p. 253 |
| Overview | p. 253 |
| The Requirements | p. 254 |
| The Environment | p. 254 |
| Making System Choices | p. 256 |
| Developing a Pointing Budget and Beam Divergence | p. 257 |
| Configuring the Communication Link | p. 258 |
| Data Rate and Modulation | p. 259 |
| Error Rate and Coding | p. 259 |
| Range Between Satellites | p. 260 |
| Transmission Budget | p. 261 |
| Aperture Sizing | p. 261 |
| Receiver Parameters | p. 262 |
| Transmit Source Power | p. 265 |
| Configuring the Track Link | p. 266 |
| The Track-Required SNR | p. 267 |
| Required Signal | p. 269 |
| The Tracking Source Power | p. 270 |
| Communication-Track Link Iteration | p. 271 |
| Configuring the Acquisition Link | p. 272 |
| Uncertainty Area Establishment | p. 272 |
| Acquisition Time and Beam Divergence | p. 272 |
| The Acquisition-Required Signal Criteria | p. 274 |
| Acquisition-Required Signal | p. 275 |
| Acquisition-Required Laser Power | p. 276 |
| Summary | p. 277 |
| Trading RF and Laser Communications for Your System | p. 279 |
| Trade Study Considerations | p. 279 |
| Factor Identification | p. 280 |
| Weight | p. 280 |
| Power | p. 281 |
| Cost | p. 281 |
| Technical Risk | p. 281 |
| Immunity From Threats (Jamming) | p. 284 |
| Nuclear Scintillation Vulnerability | p. 284 |
| Data Rate Growth | p. 284 |
| Low Probability of Intercept | p. 285 |
| Satellite Integration Impacts | p. 285 |
| Sun in the Field of View | p. 285 |
| Reliability/Life | p. 286 |
| Mutual Interference | p. 286 |
| Factor Weighting | p. 287 |
| Candidate Systems for the Example Trade Study | p. 288 |
| The Example Trade | p. 290 |
| References | p. 294 |
| Size, Weight, and Power Trends in Laser Crosslinks | p. 295 |
| Baseline Rationale | p. 295 |
| Current Technology | p. 296 |
| System Requirements | p. 297 |
| Baseline Systems | p. 297 |
| Technology Trends for Projection | p. 299 |
| Trends | p. 302 |
| System 1: A 12-Mbps, Full Duplex Twice-Synchronous-Range Crosslink | p. 302 |
| System 2: A 650-Mbps Geosynchronous to Geosynchronous Crosslink | p. 303 |
| System 3: A 1- to 6-Gbps Low Earth to Geostationary Crosslink | p. 304 |
| System 4: A Short Range 1-Mbps Crosslink | p. 305 |
| System 5: A 1- to 4-Gbps Geosynchronous to Geosynchronous Link | p. 306 |
| Size Projections | p. 306 |
| Summary | p. 307 |
| References | p. 308 |
| Laser Communications Applications | p. 309 |
| Satellite Crosslinks | p. 309 |
| Lower Data Rate, Geosynchroneous to Geosynchronous Crosslinks | p. 310 |
| High-Data-Rate Long-Range Crosslinks | p. 316 |
| Short-Range Crosslinks | p. 322 |
| Satellite to Air/Ground | p. 328 |
| Atmospheric Effects on Laser Signals | p. 328 |
| Satellite To Ground Laser Communications | p. 337 |
| Submarine Laser Communications | p. 344 |
| SLC Background | p. 345 |
| Operational Considerations | p. 346 |
| Technologies | p. 347 |
| Example System Characteristics | p. 354 |
| Deep Space Applications | p. 355 |
| Deep Space Communications Technologies | p. 357 |
| The Galileo Optical Experiment | p. 357 |
| References | p. 359 |
| Useful Formulas | p. 361 |
| Useful Physical Constants | p. 362 |
| Conversions From Optical Power to Current, Photoelectrons/Sec and Photons/Sec | p. 362 |
| Earth and Astronomical Constants | p. 362 |
| Useful Simple Optical Formulas | p. 363 |
| Useful Mathematical Expressions | p. 366 |
| General Factoids | p. 367 |
| Reference List of SPIE Volumes on Laser Communications | p. 368 |
| List of Acronyms | p. 371 |
| About the Authors | p. 375 |
| Index | p. 377 |
| Table of Contents provided by Syndetics. All Rights Reserved. |
