R a m a n S c a tt e r ing —— CCl4 molecular Raman Spectrum

1. RamanScattering ——CCl4 molecularRaman Spectrum 崔婧 09300700093

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

3. 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.

4. Introduction Classical:

5. Introduction E A1 T1 T2

6. 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.

7. 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.

8. Experiment setup

9. Data and analysis

10. Data and analysis

11. Data and analysis 样 品 池

12. Data and analysis

13. Data Data and analysis

14. Data Data and analysis

15. 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

17. Thankyou !