Answer to Question #116998 in Physics for john carry

Question

what is basic principle of Raman spectroscopy? which information can we get from Raman spectrum? which software are best to analyze Raman spectrum data?

Answer 1

1) It is the shift in wavelength of the inelastically scattered radiation that provides the chemical and structural information. Raman shifted photons can be of either higher or lower energy, depending upon the vibrational state of the molecule under study.

Stokes radiation occurs at lower energy (longer wavelength) than the Rayleigh radiation, and anti-Stokes radiation has greater energy. The energy increase or decrease is related to the vibrational energy levels in the ground electronic state of the molecule, and as such, the observed Raman shift of the Stokes and anti-Stokes features are a direct measure of the vibrational energies of the molecule. 

2)Raman spectroscopy probes the chemical structure of a material and provides information about:

• Chemical structure and identity
• Phase and polymorphism
• Intrinsic stress/strain
• Contamination and impurity

Typically a Raman spectrum is a distinct chemical fingerprint for a particular molecule or material, and can be used to very quickly identify the material, or distinguish it from others. Raman spectral libraries are often used for identification of a material based on its Raman spectrum – libraries containing thousands of Raman spectra are rapidly searched to find a match with the spectrum of the analyte.

3) If you are intending full data processing from an 2D spectrum down to intensities of selected peaks, then you might use our SpecTools. It is free-ware, LabVIEW based, so-that you can tailor it for various applications.