Raman Scattering CCl 4 molecular Raman Spectrum 09300700093

Raman Scattering ——CCl 4 molecular Raman Spectrum 崔婧 09300700093

Contents • Introduction of Raman Scattering • experiment setup • Data and analysis • conclusion

Introduction • Raman scattering or the Raman Effect is the inelastic scattering of a photon. • When photons are scattered from an atom or molecule, most photons are elastically scattered (Rayleigh scattering), such that the scattered photons have the same kinetic energy as the incident photons • However, a small fraction of the scattered photons (approximately 1 in 10 million) is scattered by an excitation, with the scattered photons having a frequency different from, and usually lower than, that of the incident photons.

Introduction Classical:

Introduction A 1 E T 1 T 2

Introduction Quantum energy level: • The Stokes and anti-Stokes spectra form a symmetric pattern above and below the absorbed photon energy. The frequency shifts are symmetric because they correspond to the energy difference between the same upper and lower resonant states.

Introduction • The intensities of the pairs of features will typically differ, though. The intensity depends on the population of the initial state of the material. At thermodynamic equilibrium, the upper state will have a lower or equivalent population and the corresponding anti-Stokes spectrum will be less intense.

Experiment setup

Data and analysis

Data and analysis

Data and analysis 样 品 池

Data and analysis

Data and analysis

Data and analysis

Conclusion • Raman spectrum——stokes and anti-stokes scattering with the same energy shift from Rayleigh scattering • Relation between the intensity of Raman scattering and temperature • depolarization ratio

T h an k yo u !