Laser Spectroscopy for Sensing
Fundamentals, Techniques and Applications
Woodhead Publishing Series in Electronic and Optical Materials Series

Laser spectroscopy is a valuable tool for sensing and chemical analysis. Developments in lasers, detectors and mathematical analytical tools have led to improvements in the sensitivity and selectivity of spectroscopic techniques and extended their fields of application. Laser Spectroscopy for Sensing examines these advances and how laser spectroscopy can be used in a diverse range of industrial, medical, and environmental applications.

Part one reviews basic concepts of atomic and molecular processes and presents the fundamentals of laser technology for controlling the spectral and temporal aspects of laser excitation. In addition, it explains the selectivity, sensitivity, and stability of the measurements, the construction of databases, and the automation of data analysis by machine learning. Part two explores laser spectroscopy techniques, including cavity-based absorption spectroscopy and the use of photo-acoustic spectroscopy to acquire absorption spectra of gases and condensed media. These chapters discuss imaging methods using laser-induced fluorescence and phosphorescence spectroscopies before focusing on light detection and ranging, photothermal spectroscopy and terahertz spectroscopy. Part three covers a variety of applications of these techniques, particularly the detection of chemical, biological, and explosive threats, as well as their use in medicine and forensic science. Finally, the book examines spectroscopic analysis of industrial materials and their applications in nuclear research and industry.

The text provides readers with a broad overview of the techniques and applications of laser spectroscopy for sensing. It is of great interest to laser scientists and engineers, as well as professionals using lasers for medical applications, environmental applications, military applications, and material processing.

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Woodhead Publishing Series in Electronic and Optical Materials

Introduction

Dedication

Part I: Fundamentals of laser spectroscopy for sensing

1. Fundamentals of optical spectroscopy

Abstract:

1.1 Introduction

1.2 Radiative processes and spectral broadening mechanisms

1.3 Atomic spectroscopy

1.4 Molecular spectroscopy

1.5 Conclusion

1.6 Acknowledgments

1.7 References

2. Lasers used for spectroscopy: fundamentals of spectral and temporal control

Abstract:

2.1 Introduction

2.2 Laser basics

2.3 Emission linewidth and emission cross-section

2.4 Cavity conditions

2.5 Spectral and temporal control

2.6 References

3. Fundamentals of spectral detection

Abstract:

3.1 Introduction

3.2 Selectivity requirements for sensing applications

3.3 Approaches to improve sensitivity

3.4 System stability and signal averaging

3.5 Conclusion

3.6 References

4. Using databases for data analysis in laser spectroscopy

Abstract:

4.1 Introduction

4.2 Definition of a database

4.3 Atomic spectroscopy databases on the Internet

4.4 Building your own database

4.5 Putting your database online

4.6 Conclusion

4.7 Disclaimer

4.8 References

5. Multivariate analysis, chemometrics, and machine learning in laser spectroscopy

Abstract:

5.1 Introduction

5.2 Preliminary notes: terminology and use of data

5.3 Feature extraction and data pre-processing

5.4 Data analysis and algorithm development: extracting information from data

5.5 Performance evaluation

5.6 Conclusion

5.7 Future trends

5.8 Sources of further information and advice

5.9 Acknowledgments

5.10 References

Part II: Laser spectroscopy techniques

6. Cavity-based absorption spectroscopy techniques

Abstract:

6.1 Introduction

6.2 Enhancement of sensitivity in absorption spectroscopy

6.3 Gas-phase cavity-ringdown spectroscopy (CRDS) and related methods

6.4 Other forms of gas-phase CRDS and related cavity-based techniques

6.5 Scope of cavity-based spectroscopy: progress and prospects

6.6 Conclusion

6.7 References

7. Photo-acoustic spectroscopy

Abstract:

7.1 Introduction

7.2 Fundamental sensitivity limitations

7 3 General considerations for photo-acoustic spectroscopy (PAS) based sensing

7.4 Practical design of photo-acoustic detectors: gas phase

7.5 Impact of energy transfer processes

7.6 Conclusion

7. 7 References

7.8 Appendix: abbreviations

8. Laser-induced fluorescence spectroscopy (LIF)

Abstract:

8.1 Introduction

8.2 Lasers and coherence

8.3 Spectral resolution

8.4 Temporal resolution

8.5 Laser-induced fluorescence (LIF) imaging and spatial resolution

8.6 LIF sensitivity

8.7 Conclusion and future trends

8.8 Sources of further information and advice

8.9 references

9. Laser-induced phosphorescence spectroscopy: development and application of thermographic phosphors (TP) for thermometry in combustion environments

Abstract:

9.1 Introduction

9.2 Thermometry methods using thermographic phosphors (TP)

9.3 Applications of TP

9.4 Conclusion and future trends

9.5 Acknowledgements

9.6 References

10. Lidar (light detection and ranging)

Abstract:

10.1 Introduction

10.2 Atmospheric spectroscopy and attenuation properties

10.3 Lidar equation and remote sensing sensitivity

10.4 Different lidar types

10.5 Lidar remote sensing examples

10.6 Conclusion and future trends

10.7 References

11. Photothermal spectroscopy

Abstract:

11.1 Introduction

11.2 Principles of photothermal spectroscopy

11.3 Methods of photothermal spectroscopy

11.4 Flow photothermal detectors

11.5 Photothermal spectroscopy in applied chemistry

11.6 Photothermal spectroscopy of solids and interfaces

11.7 Biophotothermal spectroscopy

11.8 Conclusion and future trends

11.9 References

12. Terahertz (THz) spectroscopy

Abstract:

12.1 Introduction: the historical ‘terahertz gap’

12.2 Terahertz (THz) systems based on ultrafast lasers

12.3 Terahertz sources and detectors

12.4 Applications of terahertz spectroscopy

12.5 Other terahertz applications

12.6 Conclusion and sources of further information

12.7 Acknowledgments

12.8 References

Part III: Applications of laser spectroscopy and sensing

13. Laser spectroscopy for the detection of chemical, biological and explosive threats

Abstract:

13.1 Introduction

13.2 Laser-induced breakdown spectroscopy (LIBS)

13.3 Fluorescence

13.4 Raman

13.5 Conclusion

13.6 References

14. Laser spectroscopy for medical applications

Abstract:

14.1 Introduction to spectroscopy

14.2 Energy levels in atoms, molecules and solid-state materials

14.3 Radiation processes

14.4 Absorption and emission spectra

14.5 Interplay between absorption and scattering in turbid media

14.6 Absorption and scattering spectroscopy of tissue

14.7 Fluorescence spectroscopy

14.8 Raman spectroscopy

14.9 Gas in scattering media absorption spectroscopy (GASMAS)

14.10 Conclusion and future trends

14.11 Acknowledgments

14. 12 References

15. Applications of laser spectroscopy in forensic science

Abstract:

15.1 Introduction

15.2 Research applications of laser techniques: laser-induced fluorescence (LIF)

15.3 Research applications of laser techniques: laser-induced breakdown spectroscopy (LIBS)

15.4 Research applications of laser techniques: Raman

15.5 Conclusion

15.6 References

16. Application of laser-induced breakdown spectroscopy to the analysis of secondary materials in industrial production

Abstract:

16.1 Introduction

16.2 Laser-induced breakdown spectroscopy (LIBS) analysis of industrial materials

16.3 LIBS of secondary materials in industrial production

16.4 Conclusion and future trends

16.5 Acknowledgments

16.6 References

17. Applications of laser spectroscopy in nuclear research and industry

Abstract:

17.1 Introduction

17.2 Interest of laser spectroscopy for sensing in nuclear research and industry

17.3 Laser-induced breakdown spectroscopy (LIBS) for in situ analysis and material identification

17.4 Cavity ringdown spectroscopy for ultratrace analysis in gaseous samples

17.5 Time-resolved laser-induced fluorescence (LIF) for analysis and speciation of actinides

17.6 Conclusion and future trends

17.7 References

Index

• Presents the fundamentals of laser technology for controlling the spectral and temporal aspects of laser excitation
• Explores laser spectroscopy techniques, including cavity-based absorption spectroscopy and the use of photo-acoustic spectroscopy to acquire absorption spectra of gases and condensed media
• Considers spectroscopic analysis of industrial materials and their applications in nuclear research and industry