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Energy-level diagram showing the states involved in Raman spectra. Raman spectroscopy (/ ˈ r ɑː m ən /) (named after physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. [1]
Raman spectroscopy is used to analyze a wide range of materials, including gases, liquids, and solids. Highly complex materials such as biological organisms and human tissue [26] can also be analyzed by Raman spectroscopy. For solid materials, Raman scattering is used as a tool to detect high-frequency phonon and magnon excitations.
Energy diagrams of spontaneous and coherent Raman scattering processes. Coherent Raman scattering is based on Raman scattering (or spontaneous Raman scattering). In spontaneous Raman, only one monochromatic excitation laser is used. Spontaneous Raman scattering's signal intensity grows linearly with the average power of a continuous-wave pump ...
In molecular spectroscopy, a Jablonski diagram is a diagram that illustrates the electronic states and often the vibrational levels of a molecule, and also the transitions between them. The states are arranged vertically by energy and grouped horizontally by spin multiplicity . [ 1 ]
RRS effect (Resonance Raman Scaterring) The Raman resonance effect produces an increase in Raman intensity up to 10 6 times. In this phenomenon, the monochromatic light interaction with the sample produces the transition of the molecules from the fundamental state to an excited electronic state, instead of a virtual state as in normal Raman spectroscopy.
A difference in selection rules is visible: Some bands appear only in the bulk-phase Raman spectrum or only in the SERS spectrum. Surface-enhanced Raman spectroscopy or surface-enhanced Raman scattering (SERS) is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on rough metal surfaces or by nanostructures such ...
The combination of high gain, low noise, high frequency response or, equivalently, ultra-fast response, and large area of collection has maintained photomultipliers an essential place in low light level spectroscopy, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, nuclear and particle physics, astronomy, medical diagnostics ...
Transmission Raman lends itself to rapid, non-invasive and non-destructive analysis of pharmaceutical dosage forms such as capsules and tablets.This addresses several limitations of traditional pharmaceutical assay techniques including limitations due to surface sensitivity (e.g., reflectance NIR), the presence of phase changes due to sample preparation (liquid chromatography) or sub-sampling ...