Raman Effect:
fingerprinting the universe-Excerpts from 2010
Times of India
Sir CV Raman won
the 1930 Nobel Prize for discovering the "Raman effect".
His discovery has
finally become a breakthrough technology.
Raman scanners,
weighing just one-third of a kilo, are being used as Hand-held scanners at airports
to detect drugs , explosives, hazardous chemicals and gases.
Police forces are
using Raman scanners for forensic work.
The scanners work
by detecting the molecular structure of the object they are scanning.
When a beam of
light falls on an object, a very small part of it interacts with the atoms of
the object and scatters light in a pattern which is unique for a particular
molecule. This is the Raman Effect.
Raman scattering is
difficult to detect
Lasers are needed
to amplify the signal.
Every molecule has
a different Raman pattern and hence Raman scanning is called the fingerprinting
of the universe
Normally to find
the chemical composition of a substance we need to carry out many chemical and
physical tests. This is a time consuming process. In this process we use the
substance taken for analysis and hence it is a destructive process. Raman
scanning takes just 20 seconds. It does not require cutting, extracting or
destroying a substance.