7/12/2023 0 Comments Rayman weberThe inelastic scattering of light was predicted by Adolf Smekal in 1923 and in older German-language literature it has been referred to as the Smekal-Raman-Effekt. In 1908, another form of elastic scattering, called Mie scattering was discovered. The intensity of Rayleigh scattering is about 10 −3 to 10 −4 compared to the intensity of the exciting source. The elastic light scattering phenomena called Rayleigh scattering, in which light retains its energy, was described in the 19th century. The effect had been predicted theoretically by Adolf Smekal in 1923.įirst page to Molecular Diffraction of Light (1922) Raman was awarded the 1930 Nobel Prize in Physics for his discovery of Raman scattering. Raman, who discovered it in 1928 with assistance from his student K. The Raman effect is named after Indian scientist C. Because of conservation of energy, the material either gains or loses energy in the process. An even smaller fraction of the scattered photons (approximately 1 in 1 million) can be scattered inelastically, with the scattered photons having an energy different (usually lower) from those of the incident photons-these are Raman scattered photons. Rayleigh scattering usually has an intensity in the range 0.1% to 0.01% relative to that of a radiation source. When photons are scattered, most of them are elastically scattered ( Rayleigh scattering), such that the scattered photons have the same energy ( frequency, wavelength and color) as the incident photons but different direction. Light has a certain probability of being scattered by a material. ![]() More complex techniques involving pulsed lasers, multiple laser beams and so on are known. Many other variants of Raman spectroscopy allow rotational energy to be examined (if gas samples are used) and electronic energy levels may be examined if an X-ray source is used in addition to other possibilities. The effect is exploited by chemists and physicists to gain information about materials for a variety of purposes by performing various forms of Raman spectroscopy. This is called normal Stokes Raman scattering. Typically this effect involves vibrational energy being gained by a molecule as incident photons from a visible laser are shifted to lower energy. ![]() Raman scattering or the Raman effect ( / ˈ r ɑː m ən/) is the inelastic scattering of photons by matter, meaning that there is both an exchange of energy and a change in the light's direction.
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