Rb saturated spectrum and identification of absorption lines

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Discussion Overview

The discussion revolves around identifying absorption lines in a saturated spectrum of rubidium (Rb), specifically focusing on the isotopes Rb85 and Rb87. Participants explore the experimental setup, data interpretation, and challenges in extracting meaningful information from the spectrum.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant presents a saturated spectrum of Rb and seeks help in identifying absorption lines, noting the presence of Rb85 and Rb87 isotopes and specific transitions.
  • Another participant requests more details about the experimental setup and expresses confusion regarding the axes of the spectrum graph.
  • A participant clarifies that the absorption spectra were measured using an oscilloscope with a laser beam passing through a glass cell containing Rb, and explains the process of capturing the spectrum.
  • Concerns are raised about the utility of the graph without a clear understanding of the x-axis, which is initially described as time.
  • A participant later claims to have resolved the issue by recalculating the x-axis in frequency units based on identified absorption lines from publications.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the spectrum and its axes. While some participants agree on the need for clarity in the x-axis, there is no consensus on the identification of the absorption lines or the overall interpretation of the spectrum.

Contextual Notes

Limitations include the lack of precise definitions for the x-axis and the uncertainty surrounding the experimental details, which may affect the interpretation of the spectrum.

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Hello guys, i have saturated spectrum of Rb. My goal is to identify which lines i see.

http://imagizer.imageshack.us/a/img835/8787/xvwr.png
So from http://www.opticsinfobase.org/oe/fulltext.cfm?uri=oe-15-10-6293
I have identified that there are to 2 Isotopes: Rb85 and Rb85,
further from
http://www.coldatoms.com/en/researc...laryzacja-fali-zanikajcej-eksperyment-rb.html
i identified that there are transitions 5S1/2, F = 2 → 5P1/2, F’ = 1 and 2.
And from here
http://steck.us/alkalidata/rubidium87numbers.pdf
i calculated corresponding frequencies ω1 and ω2.

Now,i do not have a clue how to identify Rb85 lines,because there are a lot of possible transitions. I think that in Rb85 lines the middle one is resonance line, and i have to identify 2 more.
Someone help?
 
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If you want some help, you'll have to give more details. What experimental setup are you using? What kind of spectrum is that? I can't read the y axis, and I don't understand why the x-axis is time.
 
DrClaude said:
If you want some help, you'll have to give more details. What experimental setup are you using? What kind of spectrum is that? I can't read the y axis, and I don't understand why the x-axis is time.

I measured absorption spectra with oscilloscope,the laser beam went through glass cell.Inside the cell was Rb.
The beam went through the cell 1 time (in one direction) and spectra was registered . This spectra in the picture is the one above,which does not give absorption lines.

The beam was reflected and it traveled through the cell again (in the opposite direction) and the spectrum was registered again. This spectra in the picture is the one with absorption lines.

The y-axis is normalized intensity. And x-axis is unknown,it just is some-kind of displacement.

I need help,because I have so little information my self. I measured it a while back and do have little details about this experiment:(

I hope this information gives more understandable point of view.
 
I'm no spectroscopist, but I don't get how you can extract any useful information from that graph if you don't know precisely what the x-axis corresponds to.
 
DrClaude said:
I'm no spectroscopist, but I don't get how you can extract any useful information from that graph if you don't know precisely what the x-axis corresponds to.

Yes,that was the problem
I think i solved it.

How i sad earlier -i identified two absorption lines by looking into publications. So if i know frequency of two lines, i calculated the ω1-ω2 and then calculated the same for x-axis position. And then recalculated all the x-axis in frequency units.
 

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