About Book

An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity or one in which feedback from the cavity is suppressed. Optical amplifiers are important in optical communication and laser physics. Optical amplifiers are used extensively in fiber optic data links. Fundamental problem in engineering are now being solved by optical methods. Stress on materials, thermodynamic properties, elasticity are some of the factors that can be measured or estimated by using optical techniques. The physics behind all these powerful methods is very rich, goes from spectroscopy to photoelasticity. Optical science gets studied in many related disciplines including astronomy, various engineering fields, photography and medicine. This book attempts to understand the multiple branches that fall under the discipline of optical amplifier and how such concepts have practical applications. It provides detailed information about optical demultiplexing, semiconductor optical amplifiers, numerical modelling, resonator amplifiers, optical pumping, laser amplifiers, quantum noise and next-generation telecommunication. Some of the diverse topics covered in this book, address the varied methodologies that comprise this subject. This book is an essential guide for both graduates and post-graduates who wish to pursue this subject further.

Preface............................................................................................................v

Chapter 1 Introductory Chapter: A Revisit to Optical Amplifiers.....................1

1 Introduction............................................................................................1

2. The mechanism involved.....................................................................2

3. A few different amplifier types.........................................................2

4. Applications...........................................................................................7

5. Current scenario....................................................................................7

6. Summary.................................................................................................8

Chapter 2 Optical Amplifiers for Next-Generation Telecommunication........12

Abstract ................................................................................................12

1. Introduction..........................................................................................12

2. Optical amplifier properties..............................................................14

3. Design and model of SOA and FRA circuit.................................21

4. Propagation and amplification of SOA and FRA.........................26

5. Conclusion............................................................................................40

Chapter 3 Quantum Dot-Semiconductor Optical Amplifiers (QD-SOA): Dynamics and Applications...................................................................42

Abstract.................................................................................................42

1. Introduction..........................................................................................42

2. Specific features of the QD-SOA dynamics...................................45

3. The influence of the optical injection on the QDWELL SOA

performance .......................................................................................52

4. The applications of QD-SOA in optical signal processing.........58

5. Conclusions .........................................................................................68

Chapter 4 Quantum Noise in Optical Amplifiers................................................75

Abstract.................................................................................................75

1. Introduction..........................................................................................75

2. Classical treatment..............................................................................76

3. Quantum mechanics...........................................................................78

4. Population-inversion–based amplifiers...........................................79

5. Optical parametric amplifiers...........................................................89

6. Conclusion............................................................................................97

Chapter 5 Ultra-Fast All-Optical Memory based on Quantum Dot

Semiconductor Optical Amplifiers (QD-SOA)...................................99

Abstract.................................................................................................99

1. Introduction..........................................................................................99

2. Optical packet switching (OPS).....................................................102

3. All-optical logic gates with SOA...................................................104

4. All-optical memory loop based on SOA MZI............................107

5. The theoretical model of the QD-SOA.........................................109

6. The simulation results......................................................................111

7. Conclusions........................................................................................114

Chapter 6 Gain Saturation in Optical Fiber Laser Amplifiers........................117

Abstract...............................................................................................117

1. Introduction........................................................................................117

2. Various types of fiber laser amplifiers.........................................119

3. Theory.................................................................................................120

4. The spectral line broadening..........................................................132

5. Amplification relations.....................................................................134

Chapter 7 All-optical Semiconductor Optical Amplifiers Using Quantum

Dots (Optical Pumping)........................................................................143

Abstract...............................................................................................143

1. Introduction........................................................................................144

2. Principles and design of proposed all-optical half-adders.......146

3. Operational principles of QD-SOA-based MZI switch.............149

4. Rate equation.....................................................................................154

5. Simulation results and discussion.................................................157

6. Conclusion..........................................................................................164

Chapter 8 Optimized Design of Yb3+/Er3+-Codoped Phosphate Microring Resonator Amplifiers..............................................................................169

Abstract...............................................................................................169

1. Introduction........................................................................................170

2. Yb3+/Er3+-codoped microring resonator model.............................171

3. Numerical analysis of an active add-drop filter.........................179

4. Gain/oscillation requirements for a symmetric structure.........183

5. Gain/oscillation requirements for an asymmetric structure.....185

6. Conclusions........................................................................................189

Acknowledgements...........................................................................189

Chapter 9 Efficient and Validated Time Domain Numerical Modeling of Semiconductor Optical Amplifiers (SOAs) and SOA-based Circuits.......................................................................................................193

Abstract ..............................................................................................193

1. Introduction........................................................................................194

2. Established SOA numerical models..............................................196

3. Accurate Transfer Matrix Method (TMM) SOA model............198

4. Gain parameterization procedure..................................................201

5. Efficient multigrid SOA model with adaptive time stepping

(TS).......................................................................................................208

6. Circuit-level simulation and applications....................................213

7. Conclusions........................................................................................216

Acknowledgements...........................................................................216

Chapter 10 Gallium Nitride-based Semiconductor Optical Amplifiers..........222

Abstract...............................................................................................222

1. Introduction........................................................................................222

2. Characterization of continuous wave light amplification.........225

3. Pulse amplification............................................................................230

4. Potential applications.......................................................................236

5. Conclusion..........................................................................................238

Acknowledgements...........................................................................238

Chapter 11 Optical Demultiplexing Based on Four-Wave Mixing in Semiconductor Optical Amplifiers ....................................................243

1. Introduction........................................................................................243

2. Analytical model ..............................................................................245

3. FWM characteristics in SOAs with the solitary probe pulse .254

4. Optical DEMUX characteristics in SOAs with multi-bit probe

or pump pulses ................................................................................260

5. Conclusion..........................................................................................268

6. Acknowledgments ...........................................................................268

Citation......................................................................................................275

Index...........................................................................................................277

About Author

Ivan McGarry obtained his Ph.D. in Physics from Technological University, Lorraine. His expertise is in quantum optics, optical coherence tomography, nonlinear optics, quantum systems and condensed matter. His interest includes spintronic devices and correspondences between general relativity and condensed matter. He is an Associate Professor at Community College, Calabozo. He has written several articles, research papers, and journals on electromagnetic radiation, geometric optics, and quantum mechanics. He also serves on the editorial board of two renowned international journals.