Chapter 9 - Spectroscopic Imaging

Different probe analytical techniques, giving rise to a variety of de-excitation processes involving ions, neutrals, energetic photons or electrons, were discussed in Chapters 5–8. In this chapter, we will discuss imaging techniques that offer intrinsic chemical selectivity for the detection of molecules due to specific vibrational frequencies in the ultraviolet, visible (Vis) and infrared ranges of the electromagnetic spectrum. These still form the basis of observation, visualisation and chemical analysis for the exploration of phenomena, from the very small (with the microscope) to the very large (with the telescope). The topics covered in this chapter include spectroscopic imaging techniques with Fourier transform infrared imaging, fluorescence microscopy and imaging, nonlinear optical microscopy, Raman imaging and laser-induced breakdown spectrometry. Important combinational tools for imaging such as the correlative use of light and electron microscopy, scanning near-field optical microscopy as well as super-resolution imaging techniques are also discussed. Instrumental and methodological developments are driven by applications in the biological and medical fields.