National Science Day

Raman sensed nano-world in 1928!

February 28 was National Science Day. Our achievement in basic science goes back to 1930 when Sir CV Raman won the Nobel Prize. We celebrate our National Science Day on February 28, because Raman announced his findings to the world on this day in 1928.
What really is the Raman Effect? Normally when the light gets transmitted through matter it is scattered in random directions. Most of the scattered light is of the same frequency (or wavelength) as the incident one. This is called ‘Rayleigh’s scattering’, but there are some parts of the radiation (1 in 10 million) which change their frequency according to the matter or properties of matter and have a frequency different from the incident radiation. This was noticed and proved experimentally by Raman. These shifts are causes of molecular motions. These are very weak compared to incident radiation, but Raman was able to observe and analyse it. Raman was able to sense the nano-range scattering and molecular level vibrations in 1928.

Till late 1980 it was a real challenge to apply this theory, but after the invention of high pulse laser, Raman Spectroscopy became one of the powerful techniques to analyse materials.

Today, Raman scattering techniques have reached almost all fields of research. Raman spectroscopy has separate dedicated peer-reviewed International journal called Journal of Raman Spectroscopy (JRS) journal published by Wiley. Raman spectroscopy explores and aids in fields like ‘Art and Archaeology’, ‘Pigments and Paints’, ‘Biosciences’ (Bio-molecules, Cells, Bacteria, Medical Applications), ‘Vibrational Studies in Chemistry’, ‘Solid State’ (Minerals, Crystals, Glasses, Ceramics, Disordered Materials), ‘Liquids and Liquid Interactions’, ‘Nanomaterials’, ‘Phase Transitions’, ‘Pharmaceutical Studies’ and ‘High Pressure Studies’ etc.

Prof W Kiefer who is Editor-in-Chief of JRS from the University of Würzburg, Germany says in his review paper, “Raman spectroscopy has brought about many new research frontiers and resulted in an explosion of research activities crossing the boundaries of scientific disciplines. It is especially anticipated that it plays an even more important role in the research of nano or subnano samples of various kinds of single molecules.
Such features of Raman spectroscopy require that Raman spectroscopists renew their concepts and readjust themselves to the new developing trends and challenging tasks. Sometimes I am asking myself what cannot be done by Raman spectroscopy - a wonderful analytical tool for science and technology which was discovered by Sir CV Raman.” We always quote Prof Rechard Fymann as the initiator of nano-technology in his famous speech ‘There’s Plenty of Room at the Bottom.’ After seeing recent developments in Raman scattering and capabilities, we must admit that Raman sensed the nano-world way back in 1928.

(The author is working in the field of science and technology, as European fellow in Germany.)