Raman and Micro-Raman Spectroscopy

The Raman effect consists in the change in frequency of a very small fraction of monochromatic incident light due to the interaction with a molecule. This chapter presents an introduction to Raman spectroscopy that is a compromise between clarity and depth. The interaction of electromagnetic radiation with matter can be studied by measuring the absorption of infrared radiation or the scattering of light. The simplest way of visualizing the mechanisms at the basis of Raman effect is through a simplified quantum description of the interaction between light and molecule, where the radiation field is described classically. The chapter provides a brief introduction to the fundamentals of the surface-enhanced raman scattering effect. The main parts of a Raman spectrometer can be summarized as follows: laser source, optical filters, monochromator, and detector. Laser is the standard light source used in Raman spectroscopy.