Fiber Lasers: Fundamentals with Matlab(r) Modelling

ISBN-13: 9780367543488 / Angielski / Twarda / 2022 / 376 str.

Johan Meyer; Justice Sompo; Sun? Von Solms

Opis

The book is an introduction to the fundamentals of fiber lasers. It provides clear explanations of physical concepts supporting the field of fiber lasers. Fiber lasers characteristics are analyzed theoretically through simulations derived from numerical models.

Spis treści

1 FUNDAMENTALS OF FIBRE LASERS 1.1 Introduction 1.2 Interest of Lasers in Fibre Form 1.3 Chronological Review of Fibre Lasers 1.1.1 Erbium and the Ytterbium co-doping 1.1.2 Continuous-wave and pulsed fibre lasers 1.1.3 Single longitudinal mode fibre lasers 1.1.4 Power scalability and high power fibre lasers 1.1.5 Other types of fibre lasers 1.4 Fibre Laser Applications 1.1.6 Manufacturing 1.1.7 Medical Applications 1.1.8 Spectroscopy 1.1.9 Various scientific applications 1.5 Conclusion 1.6 References 2 OPTICAL FIBRES 2.1 Introduction 2.1.1 Ray optic description 2.1.2 Total Internal Reflection (TIR) 2.1.3 Optical fibre 2.1.4 Meridional and skewed rays 2.1.5 Propagating modes of in an optical fibre 2.1.6 Single-mode and multi-mode fibre 2.1.7 Step index and graded-index fibre 2.2 Wave Optic Description 2.1.8 Number of transverse modes. 2.1.9 Linearly polarized (LP) modes 2.3 Attenuation and losses in Optical Fibres 2.1.10 Attenuation Coefficient 2.1.11 Material Absorption 2.1.12 Rayleigh scattering 2.1.13 Bending losses 2.4 Dispersion in Single-Mode Fibres 2.1.14 Modal dispersion 2.1.15 Group velocity dispersion 2.1.16 Material dispersion 2.1.17 Waveguide dispersion 2.1.18 Polarization mode dispersion 2.5 Non-linear effects in optical fibre 2.1.19 Stimulated Light Scattering 2.1.20 Stimulated Brillouin scattering 2.1.21 Stimulated Raman Scattering 2.6 Optical fibre materials 2.1.22 Silica glass 2.1.23 Fluoride glass and ZBLAN 2.1.24 Other types of glass 2.7 Optical Fibre Fabrication Techniques 2.1.25 Vapour Phase Deposition Methods 2.1.26 Vapour Axial Deposition (VAD) 2.1.27 Rare-earth doped fibre fabrication techniques 2.1.28 Fibre drawing from a preform 2.8 Summary APPENDIX Appendix 2.1 MATLAB program for propagation constant b as a function of normalized frequency V. Appendix 2.2 Matlab program for Bessel function of the first kind. Appendix 2.3 Matlab program for Bessel function of the second kind (Neumann functions). Appendix 2.4 Matlab program for modified Bessel function of the first kind. Appendix 2.4 Matlab program for modified Bessel function of the second kind. References 3 RARE-EARTH IONS AND FIBRE LASER FUNDAMENTALS 3.1 Introduction 3.2 General Properties and Electronic Structure of Rare-Earths 3.3 Energy Levels of Rare-Earth Ions 3.1.1 Atomic interactions of the free ions and crystal field influence 3.1.2 Terms symbols – Spin-orbit coupling 3.1.3 Atomic interactions and energy levels splitting 3.4 Light Emission and Absorption by Lanthanides – Basis Aspects 3.1.4 Selection rules 3.1.5 The “Puzzle” of 4f Electron Optical Spectra – Selection rules 3.5 Intensities of One-Photon Transitions – Judd-Ofelt Theory 3.6 Light – Matter Interaction 3.1.6 Blackbody Radiation 3.1.7 Boltzmann’s Statistics 3.1.8 Radiation-Matter Interaction —Einstein Coefficients 3.1.9 Transition Cross Section 3.1.10 Ladenburg-Fuchtbauer Relation 3.1.11 McCumber Theory of Emission Cross Sections 3.1.12 Lifetimes 3.7 Linewidth and Broadening 3.1.13 Homogeneous broadening 3.1.14 Natural broadening 3.1.15 Collisional Broadening 3.1.16 Inhomogeneous broadening 3.8 Ions-Ions Interaction 3.1.17 Energy transfer mechanisms 3.1.18 Cooperative up-conversion 3.1.19 Cross relaxation 3.9 General Considerations on Fibre Laser Operation 3.1.20 Laser general gain coefficient 3.1.21 Resonators: Linear and Ring cavity References 4. MATHEMATICAL METHODS FOR FIBRE LASERS 4.1 Introduction 4.2 Rate equations for the gain medium 4.1.1 Two energy levels systems 4.1.2 Systems with more than 3 energy levels. 4.3 Coupled propagation equations 4.4 Solutions algorithms 4.5 Shooting methods 4.6 Relaxation methods 4.7 Finite difference methods 4.8 Conclusion References 5. CONTINUOUS-WAVE SILICA FIBRE LASERS 5.1 INTRODUCTION 5.2 ARCHITECTURE AND THEORY OF OPERATION Amplifying medium Optical resonators and feedback 5.3 CONTINUOUS WAVE FIBRE LASER MODELING Formalism Linear cavity fibre laser Ring cavity fibre laser The case of DFB fibre lasers DFB fibre laser Output power computation 5.4 Conclusion 5.5 Matlab code Output characteristics of ring cavity fibre laser computed with shooting algorithm Function “propa” called in the above function Script to compute Fabry-Perot fibre laser characteristics in the case of forward pumping Script to compute the characteristics of Fabry-Perot fibre laser in the backward pumping scheme Pump power forward Pump power backward Laser power forward Laser power backward Population density function Uniform grating π-phase shifted fibre Bragg grating Shooting algorithm for simple DFB fibre laser without CUP Shooting algorithm for DFB fibre laser with CUP DFB Simulation DFB Simulation2 Rate equations single solver Rate equation pair solver 5.6 REFERENCES 6. Q-switched Fibre laser 6.1 Introduction: working principle 6.2 Fundamental mathematical description 6.3 Switching methods 6.4 Active Q-switched Fibre lasers 6.1.1 Mechanical devices 6.1.2 Electro-optic modulator 6.1.3 Acousto-optic modulator 6.5 Passive Q-switched fibre lasers 6.6 Theoretical analysis of Active Q-switched fibre laser 6.1.4 Gain medium modelling with rate equations 6.1.5 Solution algorithm 6.1.6 Parameters used in the simulation 6.7 Characteristics of the active Q-switched fibre laser 6.1.7 Influence of the length of the doped fibre 6.1.8 Influence of the pump power 6.1.9 Influence of concentration 6.1.10 Influence of AOM rise time 6.1.11 Influence of the core diameter 6.1.12 Influence of the AOM repetition rate 6.8 Modelling of passive Q-switched fibre laser 6.1.13 Type of saturable absorbers 6.1.14 Rate equations of Passive Q-switched fibre laser 6.9 Q-switched fibre laser: State of the art. 6.10 Matlab code 6.1.15 Active Q switch fibre laser function 6.1.16 Distribution function 6.1.17 Multiple pulse active Q switched function 6.1.18 Long Cavity active Q switched function 6.1.19 Laser Output function 6.1.20 Propa function 6.1.21 Boundary function 6.1.22 Boundary2 function 6.1.23 Passive Q-switched fibre laser 6.1.24 Script to plot the dynamics of the output characteristics of Passive Q-switched fibre laser 6.11 References 7 NARROW LINE-WIDTH FIBRE LASERS 7.1 Introduction 7.2 Fundamental concepts of Narrow Linewidth Fibre Lasers 7.3 Narrow linewidth fibre lasers 7.4 Linear cavity single longitudinal mode fibre lasers 7.1.1 Tunable short cavity lasers 7.1.2 Efficiency enhancement Yb3+ co-doping 7.5 Ring cavities Single Longitudinal Mode Fibre Lasers References 8. HIGH POWER FIBRE LASERS 8.1 Introduction 8.2 High Power Fibre Lasers Design 8.1.1 Cavity configurations 8.3 Increasing output power: cladding pumping 8.1.2 Brightness Enhancement in Cladding Pumped Fibre Lasers 8.1.3 Cladding-Pumping Scheme 8.1.4 Pump Combination Schemes 8.4 Rare-earth ions for high-power fibre lasers 8.5 High-Power Fibre Laser Efficiency 8.6 Beam Quality Analysis 8.7 Doped and Undoped fibres 8.1.5 Rare Earth doped fibres 8.1.6 Undoped Fibres for High Power Applications 8.8 Detrimental Effect Affecting High Power Operation 8.9 Stimulated Brillouin and Stimulated Raman Scattering 8.1.7 Stimulated Raman Scattering 8.1.8 Stimulated Brillouin Scattering 8.10 Self-Phase Modulation and Four-Wave Mixing 8.11 Influence of Optical Damage 8.12 Influence of Photo darkening 8.13 Influence of Transverse Mode Instabilities (TMI) 8.14 Working Regimes of High-Power Fibre Lasers 8.1.9 Single Fibre, Single Mode CW output power 8.1.10 Pulsed Fibre Laser Parameter Space 8.15 Other fibre lasers 8.16 Conclusion References