Effects of High-Power Laser Radiation

Effects of High-Power Laser Radiation describes the interactions between high-power laser beams and matter. This book is divided into eight chapters that particularly focus on interactions such as heating, melting, vaporization, and plasma production.

The opening chapters examine the laser properties, types, measurement techniques, and safety aspects. The succeeding chapters deal with a variety of physical phenomena and mechanisms of laser-induced particle emission, as well as the initiation and development of gas breakdown phenomena. Other chapters explore the effects and damage of various interactions in transparent materials and on biological systems. The final chapter looks into the practical applications of the various laser effects to diverse technological fields.

This book will prove useful to scientists interested in the physical phenomena of laser effects and engineers interested in practical applications of laser effects.

Preface

Acknowledgments

Chapter 1. Properties of Lasers

A. Introduction

B. Time Behavior of Laser Output

C. Mode Properties of Lasers

D. Spatial Distribution

E. Focusing Properties of Laser Radiation

F. Laser Types

References

Chapter 2. Measurement Techniques

A. Introduction

B. Power Measurements

C. Energy Measurements

D. Direct Viewing of Laser Beams

E. Measurements in the Far Infrared

F. Photographic Techniques

G. Measurement of Spatial Distribution and Beam Divergence

H. Picosecond Pulses

I. Summary

References

Chapter 3. Effects Caused by Absorption of Laser Radiation at Opaque Surfaces

A. Introduction

B. Heating without Phase Change

1. One-Dimensional Case

2. Temperature Profiles for a Laser Pulse with a Typical Shape

3. Heating by Continuous Lasers

4. Heating of Thin Sheets

5. Comparison of Calculated Values to Experiment

C. Laser-Induced Melting

D. Laser-Produced Vaporization

1. Vaporization Produced by Normal Laser Pulses

2. Vaporization by Q-Switched Laser Pulses

E. Further Studies on Laser-Irradiated Surfaces

1. Reduction of Reflectivity

2. Generation of Shock Waves

3. Metallurgical Studies

References

Chapter 4. Laser-Induced Particle Emission

A. Electron Emission

1. Observations Using Normal Pulse Lasers

2. Observations Using Q-Switched Lasers

3. Electron Sources

4. Multiphoton Emission

B. Ion Production

1. Thermionic Emission of Ions

2. Interpretation of Ion Pulse Shapes

3. Ion Energy Measurements

4. Mass Spectrometric Measurements

5. Angular Distribution of Ion Emission

6. Summary

C. Neutral Molecule Emission

D. Plasma Production

1. Experimental Studies

2. Interpretation of Results

E. Charged Particle Emission from Transparent

Dielectric Materials

References

Chapter 5. Gas Breakdown

A. Introduction

B. Initiation of Gas Breakdown

1. Absorption of Laser Light

2. Threshold of Breakdown

C. Development of Breakdown

1. Plasma Expansion

2. Charge Collection

3. Loss Processes

D. Radiation from the Spark

1. Optical Spectroscopy

2. X-Ray Emission

3. Temperatures in Laser Sparks

4. Electron Densities

E. Breakdown by Subnanosecond Laser Pulses

F. Other Experimental Studies

1. Metal Vapors

2. Spark Generation by Unusual Types of Lasers

G. Analysis

1. Initiation

2. Growth of Ionization

3. Expansion of Spark

4. Computer Calculations

References

Chapter 6. Damage in Transparent Materials

A. Introduction

B. Phenomena Associated with Damage

1. Self-Trapping of Optical Beams

2. Stimulated Brillouin Scattering

C. Experimental Results on Damage in Transparent Solids

1. Forms of Damage

2. Light Absorption and Emission

3. Damage Thresholds

4. Factors Affecting Damage

5. Photoconductivity

6. Self-Focusing Effects

D. Mechanisms of Damage

1. Hypersonic Waves

2. Multiphoton Absorption

3. Intraband Absorption

4. Absorption at Defects

5. Microplasmas—High Temperatures

6. Superposition of Stress Waves

7. Surface Damage

8. Summary

E. Effects in Transparent Liquids

F. Damage in Semiconductors

G. Damage to Laser Components

1. Damage in Ruby Rods

2. Damage in Neodymium Glass

3. Damage in Other Laser Components

References

Chapter 7. Laser Effects on Biological Systems

A. Introduction

B. Effects of Laser Radiation on the Eye

1. Laser Damage to the Retina

2. Mechanisms of Retinal Damage

3. Retinal Irradiance

4. Effects on Eye Structure Other Than the Retina

5. Effects of CO2 Lasers on the Eye

6. Summary

C. Laser Effects on the Skin

D. Effects on Deep-Lying Organs

E. Applications of Biological Effects of Laser Radiation

F. Safety Aspects of Lasers

References

Chapter 8. Applications of Laser Effects

A. Introduction

B. Laser Metalworking

1. General Considerations

2. Welding

3. Hole Drilling

4. Balancing

5. Oxygen-Assisted Cutting

6. Systems Considerations

7. Summary

C. Machining of Nonmetallic Materials

1. Drilling

2. Cutting

3. Scribing

4. Fracturing

5. Welding

D. Laser Fabrication of Electronic Components

1. Welding

2. Material Removal

E. Spectrochemical Analysis

F. Recording Applications

G. Charged Particle Sources

H. Miscellaneous Applications of Laser Effects

1. Flash Thermal Diffusivity Measurements

2. Evaporation of Thin Films

3. Simulation of Radiation Effects

4. Summary

References

Author Index

Subject Index