OpenRAMAN: cuvette and cuvette holder reflections

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NaHBrO
Posts: 18
Joined: Tue Apr 11, 2023 12:52 pm

OpenRAMAN: cuvette and cuvette holder reflections

Post by NaHBrO »

Hello forum,
I finished assembling our build and calibrated it using Hg and Na lamps. When looking at the camera picture I saw brought spectral lines of both mercury and Na as I would have expected. I then tried to make an experiment similar to the ethanol-methanol concentration as described in this archive article:
https://www.thepulsar.be/article/quanti ... ctroscopy/
the only difference was that I used isopropanol instead of methanol. When the data came back however it showed no pattern whatsoever. I tried to find out what went wrong and then I noticed that the glascuvette would reflect alot of light that would then hit the camera. The lenses of the cuvette holder also reflected some light but not to the extend of the glastube. I will try to reorient the edge filter and get rid of the stray light that way but if others have had this problem, let me know if there are other solutions out there.
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Luc
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Re: OpenRAMAN: cuvette and cuvette holder reflections

Post by Luc »

Yes that's expected; the FEL550 is there for that :)

With uncoated glass you can expect ~4% reflection. Also, elastic scattering is order of magnitudes higher than Raman scattering so it's important to have a big cut-off for the laser light.
NaHBrO
Posts: 18
Joined: Tue Apr 11, 2023 12:52 pm

Re: OpenRAMAN: cuvette and cuvette holder reflections

Post by NaHBrO »

Thank you.
Good to know that this is not an error of my setup. I now managed to block the laserlight from the spectroscope and I recalibrated it using the two gaslamps. Let's see if the spectrometer works now.
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