what is the raman effect?

Question

just for knowledge sake

Answer 1

Sir CV Raman of India was awarded the Nobel Prize for the discovery of new properties of light refraction and spectrums. He saw and found out why and how light refracts in water and the spectrum it creates. This process of light refraction is known as the 'Raman Effect'.

Answer 2

Raman scattering or the Raman effect is the inelastic scattering of a photon.

When light is scattered from an atom or molecule, most photons are elastically scattered (Rayleigh scattering). The scattered photons have the same energy (frequency) and, therefore, wavelength, as the incident photons. However, a small fraction of light (approximately 1 in 107 photons) is scattered at optical frequencies different from, and usually lower than, the frequency of the incident photons. In a gas, Raman scattering can occur with a change in vibrational, rotational or electronic energy of a molecule (see energy level). Chemists are concerned primarily with the vibrational Raman effect.

In 1922, Indian physicist Chandrasekhara Venkata Raman published his work on the "Molecular Diffraction of Light," the first of a series of investigations with his collaborators which ultimately led to his discovery on 28 February 1928 of the radiation effect which bears his name. The Raman effect was first reported by C. V. Raman and K. S. Krishnan, and independently by Grigory Landsberg and Leonid Mandelstam in 1928. Raman received the Nobel Prize in 1930 for his work on the scattering of light. In 1998 the Raman Effect was designated a ACS National Historical Chemical Landmark in recognition of its significance as a tool for analyzing the composition of liquids, gases, and solids.

Applications
Raman spectroscopy employs the Raman effect for materials analysis. The frequency of light scattered from a molecule may be changed based on the structural characteristics of the molecular bonds. A monochromatic light source (laser) is required for illumination, and a spectrogram of the scattered light then shows the deviations caused by state changes in the molecule.

Raman spectroscopy is also used in combustion diagnostics. Being a completely non-intrusive technique, it permits the detection of the major species and temperature distribution inside combustors and in flames without any perturbation of the (mainly fluid dynamic and reactive) processes examined.

Stimulated Raman transitions are also widely used for manipulating a trapped ion's energy levels, and thus basis qubit states, in ion trap quantum computing.

Answer 3

RAMAN EFFECT [Raman effect] , appearance of additional lines in the spectrum of monochromatic light that has been scattered by a transparent material medium. The effect was discovered by C. V. Raman in 1928. The energy and thus the frequency and wavelength of the scattered light is changed as the light either imparts rotational or vibrational energy to the scattering molecules or takes energy away. The line spectrum of the scattered light will have one prominent line corresponding to the original wavelength of the incident radiation, plus additional lines to each side of it corresponding to the shorter or longer wavelengths of the altered portion of the light. This Raman spectrum is characteristic of the transmitting substance. Raman spectrometry is a useful technique in physical and chemical research, particularly for the characterization of materials.

Answer 4

It is interesting to note that most of the discoveries in physics are accidental(for ex..Newton's discovery).
but.....
RAMAN EFFECT is not a accident but result of a prolonged research...
he found out that a monochromatic light when passed thro' a substance gets scattered and the scattered light has additional frequencies other than the incident frequency.
these lines r named as stokes and antistokes lines.
ok....(hope this will be useful to u).

Answer 5

let me tell u first that i m a student of college where RAMAN EFFECT was dicovered... yes the great presidency college chennai9university of madras)... it was the physics lab where cv raman did all his expt.. and i m pursuing BSc phy in same dept.. i ll like to say u that please visit the scientific american link to get ur answer.. its really not possible for me to explain u raman effect in this small space..
regards
shanu

Answer 6

when one light ray with certain freq. is splitted into two different freq's ,one is with low and one is with high freq. w.r.t the incident ray.the two rays are known as stokes and anti stokes lines.
this is known as raman effect.if u need more details mail me.