Corundum - Al₂O₃


What's going on here? Are these ruby laser fluorescence peaks?


Ruby

Mysore, India

Synthetic ruby boule showing Cr₂O₃ doping (701 and 704nm lines):
Sapphires are showing two pairs of peaks:

Sapphire 1

West Fork Rock Cr., Granite Co., Montana

Sapphire 2

West Fork Rock Cr., Granite Co., Montana

Sapphire 3

Madagascar

The S7031 CCD used on the Labram has an anti-reflection coated sapphire window. I did a spectrum on a first-surface mirror to get the laser line. and found a second laser line is visible in the anti-Stokes region. The laser lines are offset by 11.1nm... which happens to be the same offset for the two pair of sapphire peaks. The two laser lines seem to be causing two sets of fluorescence peaks...

Onigoroshi- Ghostbusting the Spectres in the Spectrum

12:09 PM 9/28/2018 This problem is apparently resolved by flushing the CCD with a dark scans. Successive frames were "storing" the images of previous frames. The number of dark scans needed to completely blank out the CCD and get rid of all the ghosts from previous scans depends on the exposure setting. Who says spectroscopy can't be existentially enlightening?