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Confocal Raman imaging microscope Raman microscope. The Raman microscope is a laser-based microscopic device used to perform Raman spectroscopy. [1] The term MOLE (molecular optics laser examiner) is used to refer to the Raman-based microprobe. [1] The technique used is named after C. V. Raman, who discovered the scattering properties in ...
The symmetry of a vibrational mode is deduced from the depolarization ratio ρ, which is the ratio of the Raman scattering with polarization orthogonal to the incident laser and the Raman scattering with the same polarization as the incident laser: = Here is the intensity of Raman scattering when the analyzer is rotated 90 degrees with respect ...
Stimulated Raman spectroscopy, also referred to as stimulated Raman scattering (SRS), is a form of spectroscopy employed in physics, chemistry, biology, and other fields. . The basic mechanism resembles that of spontaneous Raman spectroscopy: a pump photon, of the angular frequency , which is scattered by a molecule has some small probability of inducing some vibrational (or rotational ...
Coherent Raman scattering (CRS) microscopy is a multi-photon microscopy technique based on Raman-active vibrational modes of molecules. The two major techniques in CRS microscopy are stimulated Raman scattering (SRS) and coherent anti-Stokes Raman scattering (CARS). SRS and CARS were theoretically predicted and experimentally realized in the 1960s.
Although the inelastic scattering of light was predicted by Adolf Smekal in 1923, [3] it was not observed in practice until 1928. The Raman effect was named after one of its discoverers, the Indian scientist C. V. Raman, who observed the effect in organic liquids in 1928 together with K. S. Krishnan, and independently by Grigory Landsberg and Leonid Mandelstam in inorganic crystals. [1]
Coherent anti-Stokes Raman spectroscopy, also called Coherent anti-Stokes Raman scattering spectroscopy (CARS), is a form of spectroscopy used primarily in chemistry, physics and related fields. It is sensitive to the same vibrational signatures of molecules as seen in Raman spectroscopy , typically the nuclear vibrations of chemical bonds.
Both organic and inorganic materials possess a Raman spectrum; they generally produce sharp bands that are chemically specific. Fluorescence is a competing phenomenon and, depending on the sample, can overwhelm the Raman signal, for both bulk spectroscopy and imaging implementations. Raman chemical imaging requires little or no sample preparation.
If the wavelength of the surface plasmon matches that of an electronic transition in the sample, the Raman scattering will be greatly enhanced compared to ordinary RRS. [17] Resonance Raman microscopy: A microscope is used to focus the excitation laser onto a particular point in the sample, and spectra are collected for many such points. The ...