Mystery of the 609.6nm line

So. We begin at SELEM when we discovered a line lasing between my 604 and 612nm lines on my REO HeNe. We had no idea what it was, other than a probable 609nm. No significant figures beyond that.

So now, when Dr. Sam and I are back at our respected research facilities (some larger than others) we have the chance to do some real research. Not iphone research...

So it all starts with our first lead. The NIST database. A database of EVERY spectral line of EVERY element. Not just lasing lines, but EVERY spectral line.

Dr. Sam emails me about a 609.6nm line in Ne I. We have a lead.

All morning I did some research on this lead. Turns out there are 3 radioactive decay lines that 609.6nm is part of. The other two are 594.4 (not the standard 593.5nm yellow) and 667.8nm. there was also a mention on another document of 623.45nm but it wasn't noted as to what kind of line it was, and it was also marked "forbidden".

So we begin the search. 609.6nm IS a lasing line.

We confirmed at SELEM that my yellow and the 609.6nm lines competed for lasing. This now opens up 2 possibilities.

I did some research on the 594.4nm line. Turns out there has been some minor research on getting this line to lase when contaminated with trace amounts of Ar. It was noted that the Ar ionization would excite the Ne atoms and cause them to lase the 594.4nm. This is very itneresting.

On the NIST database, Ar has 2 lines in the 609nm spectra, specifically 609.0 and 609.88.

So now we have two possibilities, at least with any background.

The 609.6nm line could be lasing from the HeNe combination for reasons currently unknown, and it could be competing with either 593.9 or 594.4 for one reason or another.

First we need to determine the wavelength of the yellow, or if perhaps there are two yellows at play here.

Second, and more plausible. The 594.4nm line is lasing due to excitation of Ne by a trace amount of Ar in the tube ionizing. Then, the Ar itself is also ionizing at a ~609nm line. This would also explain the competition because there is such trace amounts of Ar in the tube.

To test that I would need to test the tube with a spectrometer to find any trace Ar spectral lines.

I also need to test my yellow line(s) to find out what is happening there. I have a possible method of doing this without the use of a spectrometer.

I plan to lase my LYR 173 593.9nm, and the REO on the same point. I will also get a decent lens to tighten the REO's beam. I then will wear diffraction glasses and see if the two (or 3) yellow spots are in different places. That will help to determine this. Although it will be hard to tell between lines only half a nm apart.

I need a spectrometer with accuracy below half a nm...

In all cases I'm aware of, argon needs a lot of current to lase. Like several orders of magnitude more than you'd find in a HeNe.

I considered that. Then I though that perhaps it has to do with the Ne and He interaction. Plus it "fits" to have it in the mix.

Normally Ar needs several amps to lase, though it would "fit" if it were the Ar lasing.

Although I thought of a third route. It still has the Ar contaminant. This contaminant is causing the 594.4nm to lase still. However perhaps this Ar contaminant also has similar effects on the Ne causing it's 609.6nm line to also lase. This would explain the competition between the two lines as they are both radiative decay lines of Ne.

I made a mistake earlier when I said radioactive decay lines.

A test that needs to be run involves determining whether 593.9 or 594.4 is lasing, if not both.

Ok, well, after some logic.

If the Ar isn't ionizing, then it cannot be exciting the Ne to excite to the 1s2p state and lase 594.4nm. That leaves Na and H2 as other culprits. However, Na wouldn't ionize at such low power, so H2 is left.

The studies I read used a tube of 1:45 He:H2. I do not know if similar outcomes are possible with less, but I am 100% sure that there isn't a similar mixture in my tube.

So, chances are 594.4nm is not lasing.

Then why is 609.6, and why is it competing with the probable 593.9nm stable line?

You now feel the pain I experienced while trying to find out what our multiline 589's are doing. I wonder if my college has a high-accuracy spectrometer......

Well, it is possible that the Ar is atomic transition rather than ionization. Basically the same thing a regular HeNe does. Excited atoms and their electrons changing orbit. This is plausible.

I found an article about Ar contamination. It contains all the lines in question. Had to use a friend's edu account to get it, he's going to email it to me.

"Abstract. The influence of argon impurities on the optogalvanic signal induced on
neon lines was studied experimentally and theoretically. In particular, the amplitude
and sign of the optogalvanic signal due to resonance pumping of the 609.6 nm line
of neon were found to be greatly influenced by Penning ionisation of argon atoms
by neon atoms excited to one of the 1s states. The model describes the transient
effects found experimentally and the pressure"

I've just contacted one of our physics professors. I'll see if he can offer any insight on your mystery line as well.

Edit: looks like you've got it.

Excellent, good man.

I am willing to put money on the culprit being Ar II. However, I have been scanning and absorbing information for 13 hours straight. I think my brain has had enough...but I haven't.

Don't forget to mention the possible lasing of the 594.4nm.

Hell, it might even be easier to send him my email. I wouldn't mind contacting him directly. I'll even update the thread. You have a PM waiting for you.

Recent unadded developments.

So, after taking some consideration, Ar ionization is ludicrous. There is no way it could ionize at such low power.

HOWEVER. Atomic transition is theoretically possible. It could explain the existence of the 609 nine, as Ar has 2 lines in the 609nm spectrum.

So, to edit our theories, we have the following. Now keep in mind variables from each could perhaps mix over, but these are the most "pure" possibilities.

Ok:

1: The Ar is being excited via atomic transition, this transition is then exciting the Ne to the 2p levels, and then down to 1s2 (594.4nm) and 1s4 (609.6nm).
Now the first part with the 594.4nm is something that has actually been observed. The 609.6nm theory is from the same process, since the yellow line (whether 593.9 or 594.4) competes with the 609.6nm line. So the theory is that the same process that lases 594.4nm is also lasing 609.6nm unlike previously documented. Again, all theory based on science done decades ago, maybe two times.

2: The ~609nm line is the Ar lasing via atomic transition, rather than ionization. This is, again, theoretically possible. Although greatly unproven. Again, this also explains the 594.4nm lasing due to Ar contaminant, exciting the Ne, etc, etc. Also explains the competition given the trace Ar to work with. All speculation, again.

3: Lastly. Smoke and mirrors and unknown science is causing the Ne 609.6nm line to lase without Ar, perhaps with another contaminant. Perhaps by itself somehow.

4: Another noble gas contaminant lasing. Not a very considered theory, but can't be ignored.


So, none of this can be proven without a spectrometer. I have a Verity monochrometer(sp?) coming in soon that I can use to measure up to about 0.1nm resolution. I plan to not only measure the orange, and yellow line(s), but also the discharge. If I can spot some sort of contaminant, and pinpoint the yellow and orange lines, we may have some science here to work with.

Currently it is all theory, but I have spent many hours reading this, probably more than anyone involved (all I did after I got back from SELEM, for 14hours straight, for like 3 or 4 days).

Any questions??

This is incredible. You should publish! You're doing amazing research. Can't wait to see the outcome!

Thank you for the support! Unfortunately I cannot prove anything without proper measurements.

Can't say Dr. Sam has not had a prevalent hand. Most of my time was spent researching, and emailing him documents for jargon translation. He also told me about the NIST. I just took it, ran with it, and did mass data collection. Then posted it

Once I get to meter everything and narrow the source, I will do a write-up. Not sure about publishing though, it's science that has mostly died...Had something similar happened in a semiconductor laser, or a DPSS, a different outcome may be possible..

That may very well be true... it's unfortunate, but true.

I'll still do a write-up on it.

Good! I can't wait to see it. I wish my area of research was as exciting to me as yours is! Hah.

Find an interesting one! I don't do this for work or anything.

Hah, I love my work, it's just not new physics. It gets a little old occasionally, too, since I've been working on the same problem for about two years now.