What is Raman Spectroscopy?

April 27, 2024

Researchers recently used a non-invasive laser technique known as Raman spectroscopy to identify the origin of a piece of ivory, enabling customs and law enforcement agencies to distinguish between ivory from extinct mammoths and living elephants.

About Raman Spectroscopy:

It is an analytical technique where scattered light is used to measure the vibrational energy modes of a sample.
It involves illuminating a substance with a laser and analyzing the light that is scattered off the surface of the substance. It is based on the interaction of light with the chemical bonds within a material.
It can provide both chemical and structural information, as well as the identification of substances through their characteristic Raman ‘fingerprint’.
Raman spectroscopy extracts this information through the detection of Raman scattering from the sample.
In 1928, Sir C.V. Raman introduced the "Raman effect," for which he was given the Nobel Prize in Physics in 1930.
What is the Raman Effect?
- It is a change in the wavelength of light that occurs when a light beam is deflected by molecules.
- When a beam of light traverses a dust-free, transparent sample of a chemical compound, most of the scattered light is at the same wavelength (or color) as the laser source and does not provide useful information; this is called Rayleigh Scatter.
- However, a small amount of light (typically 0.0000001%) is scattered at different wavelengths (or colors), which depend on the chemical structure of the analyte; this is called Raman Scatter.