Wavelengths of Oxygen - Calculate or Lookup Info

[pmlapl]

Hi,
I'm not a physicist. but I'm looking for the wavelengths of oxygen. I want to pump the electrons up to n=3 and I need to know what wavelengths given off from n=3 to n=2 and n=2 to n=1. I plan to use leds at those values to excite the electrons. If I had the books, I could calculate the values. I'm hoping someone out there can do it for me or look up the info and pass it on. Thanks for the help.

 

[Bill_K]

Here's a table of energy levels: http://physics.nist.gov/PhysRefData/Handbook/Tables/oxygentable5.htm

 

[pmlapl]

Thanks Bill,
I found those energy levels earlier in my searching. The problem is I don't know how to get the photon wave lengths associated with them. That was what I was hoping to find out from someone more knowlegeable than me. Where or how to get that info would be more helpful.

 

[Bill_K]

Hm, well in that case pmlapl you should have stated in the original post what you already had found, it would have saved us both some time.

The wavelength of a state is the inverse of its energy, E = h/λ. So the energy difference between two states is ΔE = h/λ₁ - h/λ₂, and the wavelength of the light emitted is the reciprocal of this ΔE, that is, ΔE = h/λ. Putting these together and solving for λ you get λ = λ₁λ₂/(λ₂-λ₁).

 

[SpectraCat]

Hi,
I'm not a physicist. but I'm looking for the wavelengths of oxygen. I want to pump the electrons up to n=3 and I need to know what wavelengths given off from n=3 to n=2 and n=2 to n=1. I plan to use leds at those values to excite the electrons. If I had the books, I could calculate the values. I'm hoping someone out there can do it for me or look up the info and pass it on. Thanks for the help.

Try http://www.rsbs.anu.edu.au/o2/O2_1_ ElectronicConfig.htm" .. keep in mind though the the data presented on that site is for liquid O2, and may not be appropriate for your purposes. In particular, the intensities of the bands are likely not the same as for gas phase oxygen, because all of the bands shown in the spectra correspond to spin-forbidden transitions.

If you are trying to excite gas phase O2, then the first wavelength that will have appreciable intensity will be at around 270 nm. I don't think that you will have much luck finding LED's at that wavelength.

Note that I have been assuming that you are planning to work with O2 .. that's because it's hard to make atomic oxygen, and there are basically no free O atoms floating around on earth, except in the upper atmosphere. However, your terminology of "n=3 to n=2 transitions" suggests that you are actually thinking about oxygen atoms when planning your experiments. If that is true, then you will have to generate the oxygen atoms somehow .. do you have that part of your problem solved already?

 

[pmlapl]

Thanks again Bill,
I really haven't made myself clear. Here's where I am: Referring to the chart you referenced, I don't know what the cm^-1 values mean. I don't know why there are two values per energy level. I searched and found a number of values for Planck's Constant. I am assuming I should use 6.262 x 10^-34 J s. I know that c= 3 x 10^8 m/s. I also found in my searching that E = hc/x where x is wavelength. Probably lambda to you. It's the "E" part that has me stumbling. Is E in cm^1 values or in kJ/Mol? Knowing that I should be able to go forward.