- #1
fsonnichsen
- 62
- 5
I have taken a time dependent fluorescence series of spectra for an ethylene glycol solution using a 532nm laser as the excitation source. I have attached the spectra to this post. Nothing looks unusual-there is a sharp notch near the 532nm line--this is due to a filter I have used to protect the spectrometer from the laser.
However--note that the spectrum has points to the left of the laser line-e.g. at wavelengths lower (energies higher) than the laser. How does this happen? I don't believe this could be attributed to Raman /anti-stokes processes due to the large separation--usually these shifts are smaller yes? Even though we are dealing with a complex solution here, we cannot expect electrons to become promoted to levels higher than the excitation photons to this extent.
thanks
Fritz
However--note that the spectrum has points to the left of the laser line-e.g. at wavelengths lower (energies higher) than the laser. How does this happen? I don't believe this could be attributed to Raman /anti-stokes processes due to the large separation--usually these shifts are smaller yes? Even though we are dealing with a complex solution here, we cannot expect electrons to become promoted to levels higher than the excitation photons to this extent.
thanks
Fritz