This book offers comprehensive, state-of-the-art information about time-domain fiber-optic testing. Readers will gain an understanding of how to troubleshoot optical-fiber networks using an optical time-domain reflectometer (OTDR), while learning the fundamental principles underlying the operation of these powerful testing instruments. From basic fiber optics and fiber testing, to detailed event-analysis techniques, this book covers the entire spectrum of time-domain optical cable test theory and applications. * Only book available focusing solely on OTDR theory and practice * Covers the entire spectrum of time-domain optical cable test theory and applications * Designed to be accessible to both engineers and system technicians * Includes OTDR training CD
Author(s): Duwayne R. Anderson
Publisher: Academic Press
Year: 2004
Language: English
Pages: 452
Team DDU......Page 1
Contents......Page 6
Foreword......Page 12
1 0 Introduction......Page 16
1 1 The birth of the OTDR......Page 17
1 2 Features, functions, and performance improvements......Page 19
1 3 Summary......Page 24
Suggested reading......Page 26
2 1 Total internal refl ection......Page 28
2 2 Fiber attenuation......Page 34
2 3 Numerical aperture......Page 38
2 4 Multipath (modal) dispersion......Page 39
2 5 Chromatic dispersion......Page 43
2 6 Wavelength-division-multiplexed systems......Page 50
2 7 V-parameter, cut-off wavelength, and spot profi le......Page 51
2 8 Splices and connectors......Page 57
2 9 Bending loss......Page 63
2 10 Coherence......Page 67
2 11 Summary......Page 70
Problems......Page 72
3 0 Introduction......Page 74
3 1 OTDR design......Page 77
3 2 A typical OTDR waveform......Page 78
3 3 Multiple-wavelength OTDRs......Page 80
3 4 Optical masking......Page 82
3 5 Evolution of the OTDR......Page 84
3 6 Rayleigh backscatter......Page 87
3 7 Dynamic range......Page 89
3 8 Differences between multimode and single-mode OTDRs......Page 93
3 8 2 Refl ectivity differences between single-mode and multimode fi ber connectors......Page 96
3 8 3 Differences in backscatter levels......Page 97
3 8 5 Pulse-width differences......Page 98
3 8 6 Operating-wavelength differences......Page 99
3 9 Echoes and ghosts......Page 102
3 10 1 Standard OTDR with an EDFA......Page 106
3 10 2 Coherent-detection OTDR......Page 108
3 10 3 Correlation OTDR......Page 110
3 10 4 Short-coherence-length coherent OTDRs (multimode)......Page 111
3 10 5 Photon-counting OTDRs......Page 113
3 11 Summary......Page 114
Suggested reading......Page 115
Problems......Page 116
4 1 Figures of merit......Page 118
4 2 Historical fi gures of merit......Page 120
4 3 Detailed fi gures of merit......Page 122
4 3 1 Refl ective dynamic range......Page 123
4 3 2 Scattering dynamic range......Page 124
4 3 3 Derivation of the noise fl oor......Page 130
4 3 4 Dynamic-range margin......Page 136
4 3 5 Usable dynamic range......Page 138
4 3 6 Measurement range......Page 139
4 3 7 How offset errors affect dynamic-range and measurement-range calculations......Page 140
4 3 8 Event resolution......Page 150
4 3 9 Loss-measurement resolution......Page 152
4 3 10 Return loss......Page 154
4 3 11 Linearity......Page 155
4 3 12 Data resolution......Page 156
4 3 13 Clock accuracy......Page 158
4 3 15 Refractive-index uncertainty......Page 159
4 3 16 1 Fiber length......Page 161
4 3 16 3 Data-processing speed......Page 162
4 3 17 Event-detection accuracy......Page 163
4 4 Standards......Page 164
4 5 Summary......Page 165
Problems......Page 166
5 1 Sources of nonrefl ective events......Page 168
5 2 Cursor placement for manual loss and distance measurements......Page 171
5 3 1 Distance-measurement errors caused by waveform noise......Page 173
5 3 2 Distance-measurement errors caused by fi ltering......Page 182
5 3 3 Other contributions to distance-measurement errors......Page 185
5 4 Summary......Page 191
Suggested reading......Page 192
Problems......Page 193
6 1 Loss-measurement errors caused by waveform noise......Page 194
6 2 Loss-measurement errors due to mismatch of single-mode fi bers......Page 200
6 3 Loss-measurement errors on multimode fi ber......Page 205
6 4 Bending loss and stress loss in single-mode fi bers......Page 211
6 5 Wavelength-dependent loss in fusion splices and connectors between single-mode fi bers......Page 213
6 6 Intrinsic loss in single-mode fusion splices......Page 215
6 7 Summary......Page 220
Problems......Page 221
7 1 Background......Page 224
7 2 1 Refl ections from angled cleaves......Page 227
7 2 2 Refl ections from connectors......Page 229
7 2 3 Refl ections from mechanical splices......Page 235
7 3 Measuring refl ective events using an OTDR......Page 236
7 4 Effects that can reduce the accuracy of refl ectivity measurements......Page 241
7 5 Calibrating the OTDR's backscatter coeffi cient......Page 244
7 5 1 Calculating the backscatter coeffi cient......Page 245
7 5 2 1 Measuring the backscatter coeffi cient with a calibrated refl ector......Page 248
7 5 2 2 Measuring the backscatter coeffi cient using a CWR......Page 250
7 5 2 3 Measuring the backscatter coeffi cient using an OTDR......Page 252
7 6 Integrated return loss......Page 255
7 7 Summary......Page 260
Problems......Page 262
8 1 Refl ections and the dead zone......Page 264
8 2 Improving the dead zone by optical masking......Page 267
8 3 Impact of refl ections on transmitters and receivers......Page 272
8 4 Dead zone box......Page 278
Problems......Page 280
9 0 Introduction......Page 282
9 1 The far-fi eld scanning method of determining numerical aperture......Page 283
9 2 Measuring the numerical aperture of single-mode fi ber using an OTDR......Page 287
9 3 Measuring the cut-off wavelength of a single-mode fi ber using an OTDR......Page 290
Suggested reading......Page 292
Problems......Page 293
10 0 Introduction......Page 294
10 1 Determining the locations of breaks in systems containing splitters......Page 299
10 2 OTDR requirements for testing networks with splitters......Page 302
Suggested reading......Page 304
Problems......Page 305
11 1 Types of event markings......Page 306
11 2 Functionality of different types of event markings......Page 308
11 3 Optimizing acquisition parameters......Page 313
11 4 Measuring individual events......Page 319
11 5 1 Test-fi ber calibration......Page 327
11 5 2 Repeatability testing......Page 329
11 6 Event-marking features......Page 332
11 7 Remote OTDRs for monitoring networks......Page 336
11 8 Summary......Page 340
Suggested reading......Page 341
Problems......Page 342
12 1 Dead zone fi xture......Page 344
12 2 Fiber circulator......Page 345
12 3 External-source test fi xture......Page 352
12 4 Loss calibration with fi ber standard......Page 353
12 5 Summary......Page 355
Suggested reading......Page 356
Problems......Page 357
13 0 Introduction......Page 358
13 1 Measurement techniques......Page 361
13 2 PMD model of optical fi ber......Page 364
13 3 Mathematical model of a polarization OTDR......Page 368
13 4 Summary......Page 372
Problems......Page 373
14 0 Introduction......Page 374
14 1 Intermodal dispersion......Page 376
14 2 1 Material dispersion......Page 379
14 2 2 Waveguide dispersion......Page 381
14 3 Dispersion reduction in optical fi bers......Page 383
14 4 Measuring dispersion using an OTDR......Page 384
14 5 Measuring chromatic dispersion using multiple-wavelength OTDRs......Page 387
14 6 Summary......Page 390
Suggested reading......Page 391
Problems......Page 392
15 0 Introduction......Page 394
15 1 Durability......Page 395
15 2 Display and controls......Page 397
15 3 Human interface......Page 401
15 4 Optical port......Page 402
15 5 Accessories, options, and features......Page 409
15 6 Safety......Page 411
15 7 Performing a fi ber-acceptance test......Page 414
15 7 1 Sequential steps of an acceptance test......Page 415
15 8 Measuring the splice attenuation......Page 417
15 8 1 Corrective actions......Page 418
15 9 When should OTDR traces be taken?......Page 419
15 10 1 What measurements are required?......Page 420
15 11 Field technician's top-ten list......Page 421
Problems......Page 422
Glossary of Terms......Page 424
Mathematical Glossary......Page 440
Answers to Problems......Page 446
Index......Page 448
