Understanding Raman Spectroscopy: Principles, Applications, and Advantages, Summaries of Commercial Law

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Raman Spectroscopy

Raman, Fluorescence and IR

Scattering

Absorption

and emission Absorption

As discussed, when an atom or molecule is brought into an electric field E , an electric dipole moment μ is induced in the system. The magnitude of this induced dipole moment is proportional to the electric field, μ = α E where α is known as the polarizability.

Change in Polarizability

Classical theory Raman scattering: Rotational Raman

Rayleigh Stokes Anti-Stokes α  0

Polarizability should be changed during rotation

• An oscillating electric field (incident photon) causes the

molecule to have an induced dipole:

• 

Classical theory Raman scattering : Vibrational Raman

Rayleigh Stokes^ Anti-Stokes  0

=

Quantum Picture of Raman scattering : Vibrational Raman

Molecular Picture of Scattering Events

Rotational Raman

Stokes (-) anti-stokes (+)

For Linear Molecules

𝝊𝟎 ± 𝑩 (𝟒𝑱 + 𝟔)