Rb saturated spectrum and identification of absorption lines

In summary, the author is trying to identify which lines in a spectrum are Rb85 lines. He uses an oscilloscope to measure absorption spectra, and then uses a mirror to reflect the beam and measure the spectrum again. He calculates the frequency of the lines based on the spectra.
  • #1
prehisto
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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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  • #2
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.
 
  • #3
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.
 
  • #4
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.
 
  • #5
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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