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Raman
Spectroscopy An Introduction to Raman Spectroscopy
Raman Spectroscopy is a very powerful method for
measuring charbo-hydrates concentrations like Gas Oil or Glucose over
distances or within difficult enviroments. It works best for large
molecules like carbo-hydrates. For atoms or small molecules, please check
for Absorption Spectroscopy.

When the light (photon) interacts with the
molecular structure of the sample, energy is transferred into grating vibrations
(phonon) of the molecule. Depending on the absorption or
the emission of a phonon, a characteristic energy is reduced or added
to the photon energy. This characterisitic energy shift is called Stokes or
Anti-Stokes Shift. The Stokes and Anti-Stokes Shift can be detected
experimentally. The exact value of the shift allows a unique identification of
most charbo-hydrates.

For applying this detection method a fixed
wavelength laser system with an excellent side mode suppression and a
spectrometer is required as shown. The purity of the laser light is increased by
a notch filter before it is coupled to the sample. There it interacts with the
sample and in result, the signal according to the Stokes and Anti-Stokes Shift
is generated. With removing the central wavlength of the laser light by an
optical filter, the shift of the raman signal can be determined by the
spectrometer. The absolute value of the shift allows the identification of the
sample material.
Application Examples are given on this website for
various carbo-hydrates. Please contact us for more detailed information.
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