I was trying to Analyze Gold electrode quality by Raman. But the problem is I often having some peak like in the picture. which I am unable to define. even I am having this kind of picture in others materials too. and I also found same peak while I am doing raman with no laser. green laser was used and filter was medium, grating 1800.
Did I get it right that you measure the signal without having the laser in operation? If yes, that would mean that you probably detect some background noise signal. What about the instrumentation?
Kind regards
Peter
If you're getting this with the laser powered off, it's probably light leakage +a fluorescent light in the lab. To confirm this, you'd need to know the laser wavelength, as the wavenumber spectrum you gave doesn't provide the absolute wavelength of the peaks.
Try to reduce any light sources in the lab. Apparently things like fluorescents may have a contribution like that to your spectrum. It would be useful to know the wavelength of those peaks instead of the shift (know the reference laser the system though you were measuring with even if it was off).
This is an example of a fluorescent spectra, but we need the wavelength to know if it fits. (Source http://www.bealecorner.org/best/measure/cf-spectrum/)
Thanks to everyone.
Mr.. Peter wagner - If it is background noise then my question will be- why I am having same peak position while doing raman with laser?
Mr. John Brindle and Julia Gala - I always do the Raman in the dark room. Do you know for pure gold where should I get the peak in Raman? waiting for your reply?
Hi Saleh. I have the same question as you. Not sure where the peak should be. I'm using 785nm laser and getting a peak around 1400.
When you do not have any photons generated by Raman activity at these wavelengths you will certainly detect photons generated by another "source" as background noise, even with laser turned on. What is the laser wavelength?
Mysterious indeed. If there's absolutely no other light possibly getting into the system ANYWHERE (and it doesn't have to be much), it's most likely to be a detector problem. The spectrum resembles that of a silicate glass, incidentally, though if you're using a commercial instrument and the laser's turned off, it won't be that. I wouldn't expect pure gold to give a Raman spectrum - no covalent bonding - and RRUFF agrees:
http://rruff.info/Gold
Final thought: you aren't actually looking at a previously recorded and saved spectrum of something else, by any chance?
I am also thinking about your final thought Mr. John. but saw it several time in between experiments so not sure... But thanks for your information
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