Inorganic Glasses for Photonics. Fundamentals, Engineering, and Applications

Table of Contents

Series Preface

Preface

1 Introduction

1.1 Definition of glassy states

1.2 The glassy state and glass transition temperature (Tg)

1.3 Kauzmann papradox and negative change in entropy

1.4 The glass-forming characteristics and thermodynamic properties

1.5 Glass formation and co-ordination number of cations

1.6 Ionicity of bonds of oxide constituents in glass forming systems

1.7 Definitions of glass network formers, intermediates and modifiers and glass-forming systems

1.7.1 Constituents of glass-forming systems

1.7.2 Strongly covalent inorganic glass-forming networks

1.7.3 The conditional glass-formers based on heavy metal oxide glasses

1.7.4 The fluoride and halide network forming and conditional glass-forming systems

1.7.5 The oxynitride conditional glass-forming systems

1.7.6 The chalcogenide glass-forming systems

1.7.7 Chalcohalide glasses

1.8 Conclusions

2 Thermal and viscosity characterizations of inorganic glasses

2.1 Introduction

2.1.1) The kinetic theory of glass formation and prediction of critical cooling rates

2.1.2) Classical nucleation theory

2.1.3) Non-steady state nucleation

2.1.4) Heterogeneous nucleation

2.1.5) Nucleation studies in fluoride glasses

2.1.6) Growth Rate

2.1.7) Combined growth and nucleation rates, phase transformation and critical cooling rate

2.2 Thermal characterisation using differential scanning calorimetry (DSC) and differential thermal analysis (DTA) techniques

2.2.1) General features of a thermal characterisation

2.2.2) Methods of characterisation

2.2.3) Determining the characteristic temperatures

2.2.4) Determination of apparent activation energy of devitrification

2.3 Coefficients of thermal expansion of inorganic glasses

2.4 Viscosity behaviour in the near-Tg, above Tg and in the liquidus temperature ranges

2.5 Density of inorganic glasses

2.6 Specific heat and its temperature dependence in glassy state

3 Bulk Glass Fabrication and Properties

3.1 Introduction

3.2 Fabrication steps for bulk glasses

3.2.1 Chemical vapour technique for oxide glasses

3.2.2 Batch preparation for melting glasses

3.2.3 Chemical treatment before and during melting

3.3 Chemical Purification Methods for Heavier Oxide Glasses (TeO2, GeO2)

3.4 Drying, Fusion and Melting techniques for fluoride glasses

3.4.1 Raw Materials

3.4.2 Control of hydroxyl ions during drying and melting of fluorides

3.5 Chemistry of purification and melting reactions for chalcogenide materials

3.6 Need for annealing after casting

3.7 Fabrication of transparent glass ceramics

3.8 Sol-gel technique for glass formation

3.8.1 Background theory

3.8.2 Examples of Materials Chemistry and Sol-gel Forming Techniques

4 Optical Fibre Design, Engineering, Fabrication and Characterization

4.1 Introduction to geometrical optics of fibres: geometrical optics of fibres and waveguides (propagation, critical and acceptance angles, numerical aperture)

4.2 Solutions for dielectric waveguides using Maxwell’s equation

4.3 Materials properties Affecting Degradation of Signal in Optical Waveguides

4.3.1 Total Intrinsic loss

4.3.2 Electronic absorption

4.3.3 Experimental aspects of determining the short wavelength absorption

4.3.4 Scattering

4.3.5 Infrared absorption

4.3.6 Characterisation of vibrational structures using Raman and IR Spectroscopy

4.3.7 Experimental aspects of Raman spectroscopic technique

4.3.8 Fourier Transform Infrared (FTIR) spectroscopy

4.3.9 Examples of the analysis of Raman and IR spectra

4.4 Fabrication of core-clad structures of glass preforms and fibres and their properties

4.4.1 A comparison of the fabrication techniques for silica and non-silica optical fibres

4.4.2 Fibre fabrication using non-silica glass core-clad structures

4.4.3 Loss characterisation of fibres

4.5 Refractive Indices and dispersion characteristics of inorganic glasses

4.5.1 Experimental procedure for measuring refractive index of a glass or thin film

4.5.2 Dependence of density on temperature and relationship with refractive index

4.5.3 Effect of residual stress on refractive index of a medium and its effect

5 Thin-film fabrication and characterization

5.1 Introduction

5.2 Physical Methods of thin and thick film deposition

5.3 Evaporation

5.3.1 General Description

5.3.2 Techniques, materials and process control

5.4 Sputtering

5.4.1 Principle of sputtering

5.5 Pulsed laser deposition

5.5.1 Introduction and principle

5.5.2 Process

5.5.3 Key Features of PLD process

5.5.4 Controlling parameters and materials investigated

5.6 Fabrication of multi-layer structures using PLD

5.7 Ion implantation

5.7.1 Introduction

5.7.2 Technique and structural changes

5.7.3 Governing Parameters for Ion Implantation

5.7.4 Materials Systems Investigated

5.8 Chemical Techniques

5.8.1 Characteristics of chemical vapour deposition processes

5.8.2 Materials System Studied and Applications

5.8.3 Molecular Beam Epitaxy (MBE)

5.9 Ion exchange technique

5.10 Chemical Solution or Sol-gel Deposition (CSD)

5.10.1 CSD Technique and Materials Deposited

6 Spectroscopic properties of lanthanide (Ln3+) and transition metal (M3+)-ion doped glasses

6.1 Introduction

6.2 Theory of Radiative Transitions

6.3 Classical Model for Dipole Motion and Decay Process

6.4 Factors Influencing the Line Shape Broadening of Optical Transition

6.5 Characterization of Dipoles and Multipoles and Selection Rules

6.5.1 Analysis of Dipole transitions based Fermi’s Golden Rule

6.5.2 The Laporte Selection Rules for Rare-earth and Transition Metal Ions

6.6 Comparison of Oscillator Strength

6.6.1 Radiative and non-radiative rate equations

6.6.2 Energy transfer and related no-radiative processes

6.6.3 Upconversion process

6.7 Selected Examples of Spectroscopic Processes in RE-ion doped Glasses

6.7.1 Spectroscopic properties of trivalent lanthanide (Ln3+) doped inorganic glasses

6.7.2 Comparison of spectroscopic properties of Er3+-doped glasses

6.7.3 Comparison of spectroscopic properties of Tm3+-doped glasses

6.8 Conclusions

7 Applications of Inorganic Photonic Glasses

7.1) Introduction

7.2) Dispersion control and management in optical fibres

7.2.1 Intramodal Dispersion

7.2.2 Intermodal distortion

7.2.3 Polarisation mode dispersion (PMD)

7.2.4 Methods of controlling and managing dispersion in fibres

7.3) Unconventional fibre structures

7.3.1) Fibres with periodic defects and bandgap

7.3.2) TIR and Endlessly Single Mode Propagation in PCF with positive core-cladding difference

7.3.3) Negative core-cladding refractive index difference

7.3.4) Control of Group Velocity Dispersion (GVD)

7.3.5) Birefringence in microstructured optical fibres

7.4) Optical nonlinearity in glasses, glass-ceramic materials and fibres

7.4.1 Theory of harmonic generation

7.4.2 Nonlinear Materials for Harmonic Generations and Parametric Processes

7.4.3 Fibre based Kerr Media and its application

7.4.4 Resonant Non-linearity in Doped Glassy Hosts

7.4.5 Second Harmonic generation

7.4.6 Electric-field poling and poled glass

7.4.7 Raman gain medium

7.4.8 Photo-induced Bragg and long-period gratings

7.5) Applications of selected Rare-earth and Bi-ion doped amplifying devices

7.5.1 Introduction

7.5.2 Examples of three-level or pseudo-three level transitions in

7.5.3 Examples of four-level lasers

7.6) Emerging opportunities for future

Supplementary References

List of Symbols and Notations Used

Index