Basics of Raman Scattering (RS) Spectroscopy

Abstract

Raman spectroscopy is an optical spectroscopic technique based on the inelastic scattering (called Raman scattering—RS) of light by the matter (the molecule of interest for instance). RS event occurs because a molecular vibration can change the polarizability of molecule which interacts with incident light. Thus, Raman spectroscopy is a vibrational technique and Raman spectra provide specific molecular fingerprint information. RS effect was discovered by Indian physicists C.V. Raman in 1928 but only instrumental developments from 1980s brought about big progress of Raman techniques. Although RS process is intrinsically weak, Raman spectroscopy has become nowadays a routine method in many fields. This chapter gives a brief introduction to Raman spectroscopy including a short history, basics of RS theory, cross-sections, vibrations, selection rules, resonant RS, polarization properties as well as Raman experiment in macroscopic and microscopic setups. The last paragraph summarizes the advantages and disadvantages of the Raman spectroscopy for biomolecular studies and the main characteristics of Raman spectra of biomolecules.