ABSTRACT
This chapter discusses the various types of laser spectroscopy techniques. Raman scattering is inelastic scattering of light with excitation or de-excitation of matter. Therefore, before the advent of lasers, Raman scattering had far less practical relevance. Today, Raman spectroscopy has a wide range of applications, including biology, medicine, temperature sensing in optical fibres, analyses of artworks, and the detection of explosives. On the other hand, Rayleigh scattering is an elastic process. Most complex molecules have characteristic fluorescence bands, which are so narrow that only laser sources can provide a required spectral power. The last three chapters discuss the importance and applications of non-linear optics in laser spectroscopy. Rapid detection and classification is important in biotechnology and medicine. High-intensity laser beam can induce optical breakdown, which can be used for spectral characterization of materials, leading to the so-called laser-induced breakdown spectroscopy.
