Questions to be addressed in your report

• What spectroscopic constants of the Iodine ground state can be extracted from your data? Do these agree with accepted values?
• What features are observed in the emission spectrum that do not correspond to sharp lines? How is this emission affected by experimental conditions? Hint, the fluorescence lifetime is affected by collisions, as we can see in this trace of the time resolved emission to the v"=2 state, taken by Oleg Matveev
• How well does the ground state of iodine correspond to a Morse Potential?
• What fraction of the total number of vibrational levels of the ground state are observed in this experiment?
• How does your dissociation limit correspond to the literature value for this molecule? How do D₀ and D_e compare? What is the theoretical difference between these values?
• Laser induced fluorescence is observed with the laser tuned to 5145, but not 4880. Why?
• What are competitive relaxation pathways to spontaneous emission of the excited state?
• What is the cause of the intensity pattern in the emission? Does this pattern depend on the Excitation (laser) frequency? Pressure? Photomultiplier spectral response?

References

Quantum Mechanics

The Harmonic Oscillator

The Born-Oppenheimer Approximation

Spectroscopy

Electric dipole transitions

Franck-Condon factor

see:Atkins "Physical Chemistry" or equivalent

Specifics about I₂ spectroscopy

See:

Huber and Herzberg "Constants of Diatomic Molecules" (Van Nostrand, New York, 1979)

R. B. Snadden "The Iodine Spectrum Revisited", J Chem Ed, 64, 919 (1987).