Sciencemadness Discussion Board

Dry ice as a laser medium

Iv4 - 13-8-2003 at 03:55

As most of you know,CO2 is one of the best laser mediums.It oprates trhough a wide degree of presure,oe of the few that are superradeint(well without like a km of resonater anyway)and operate under atmoshperic presure(and more).It's strongest line is at 10.6 PM(wt another at 9.8 or so).

Now I'm thinking that if dry ice were used the gain might be even higher because of the density and so reap the benefits of a solid state.Coments?

Nick F - 13-8-2003 at 10:00

The CO2 is mixed with He and nitrogen, IIRC, although I bet it varies from design to design. The He is excited by an electrical discharge, and it passes on its energy to the CO2 molecules, which then emit it when stimulated and are then ready to absorb more energy.
This would not be possible with solid CO2 :(.

Basement Chemist - 13-8-2003 at 10:15

Do you know any websites where more information can be found about these CO2 lasers? In physics class we just went over it in like 10 minutes....

DDTea - 20-8-2003 at 06:55

If CO2 lasers require He or N2 in order to work... Would it be possible to have a mixture of Solid CO2 and Liquid Nitrogen?

Still, I wouldn't want to be the one operating it if it has the potential to build up so much pressure.

Nick F - 20-8-2003 at 08:57

If you can find a way to ionise liquid nitrogen to the point where it is conductive, then be my guest to try it :D.

Even if you could do that, dry ice and LN2 have different densities, so the light would get scattered everywhere.

Sorry for being late

Iv4 - 6-9-2003 at 04:46

Actually rhere are soe accounts of CO2 only lasers working(with reduced effeciancy)Though you probably right.The lower effeciancy and the container needed for the presure or the cooling does'nt justify not just building a larger laser.

Iv4 - 3-10-2003 at 02:54

I was looking at gas flow dynamic lasers and it seems that if microwave pumping was used it could excite the Co2 directly.So the dry ice could be used.

Sorry about the double post.

unionised - 2-11-2003 at 09:18

Unfortunately, the colisional line broadening of the transitions would make life difficult for a liquid or solid phase CO2 laser.

perhaps dumb...

Organikum - 23-11-2003 at 09:19

what about a microwave powered sulphur UV-laser?
- see sulphur-lamp.

or got I something wrong here?

unionised - 23-11-2003 at 15:34

UV lasers are generally particularly difficult; the upper excited state lifetimes are normally rather short.

Iv4 - 23-11-2003 at 23:14

I have to disagree with you unionised.The nitrogen laser has got to be the easiest to build,specialy when in open air.

Maybe I'm missing something but arent sulpher lamps almost compltely free of UV light?

At any lenght I think that using a thioate(or however it speled)might be a good idea judging from copper halide lasers.

Organikum - 24-11-2003 at 13:01

the exited sulphur emitts UV which exites the argon to emitt visible light. Leaving away the argon should provide UV solely....

so I remember

Iv4 - 25-11-2003 at 05:44

Well I just ran a quick google search so I guess your right :).I found some site which said that the inert atmosphere is to keep the sulpher from reacting wth anything but it did sounds rather pointless.

Anyways you supose putting the sulpher in a glass matrix is a good idea?IMHO copper might benefit from this.

Organikum - 25-11-2003 at 07:37

Copper and microwave exitation? Not to talk of the heat. Quartz not glass..... Perhaps Si-oxide could be fused with tiny amounts of sulphur mixed by........

Iv4 - 26-11-2003 at 02:16

My mistake,but you know some sort of matrix like in a YAG or AlO.

The silicon oxide sounds like good idea.Just had a thought.Supose the matrix is somewhat conductive.It could be puped directly.

Organikum - 26-11-2003 at 08:13

I fear this would lead only to a meltdown of the matrix as strong cooling will be necessary anyways. To integrate a cooling feature in the matrix is the bigger task IMHO....

unionised - 26-11-2003 at 14:24

The fact that there is one easy UV laser does not detract from the fact that, in general, they are difficult.

Iv4 - 27-11-2003 at 01:44

Your right in that regard but I'm just saying that theres one very big exception :)

It could be cooled conventionaly or just maybe depending on the matrix it could be cooled magnetically.

unionised - 29-11-2003 at 08:02

Did anyone look at how the sulphur lamp works? I accept that I foolishly accepted what people had posted until I had a bit more time on my hands and checked.

Here
http://www.sulfurlamp.com/tech.htm
is some stuff about it including a spectrum of the output.
How do you intend to get UV out of that?
(Another of the sites that google found points out that the argon is just for ease of starting)
All this stuff about cooling is hardly the point when it simply doesn't generate a lot of UV and it has a broad band spectrum.

Iv4 - 29-11-2003 at 08:08

I ran a google search as well and got the same result but since I have more faith in Organikum than whoever wrote it.:)

unionised - 30-11-2003 at 05:48

Organikum did point out that he was working from memory. The website included such details as a spectrum.
OTOH I couln't be bothered to check it at the time so I can't complain too much.

Yea I guess so

Iv4 - 30-11-2003 at 20:58

Come to think of it sulpher might be a way into the legenedry white laser.Though I have no clue about getting the thing to lase or if its even possible.

I was not sure on this

Organikum - 1-12-2003 at 13:16

with the sulfur lamp - it was a question I asked.

I will have a look in my archives later today and do a websearch on my own for to provide clearification.

peace
ORG

Iv4 - 2-12-2003 at 23:44

New branch.Co2 infuse in a Al2)3(or something)matrix.

unionised - 3-12-2003 at 15:09

You will perturb the energy levels of the CO2 and so it won't work the same way as the gas phase; it might work, but then it probably wont.

Iv4 - 4-12-2003 at 02:49

You mean because of the matrix absorbing the sapphire absorbing energy?If so you might have a stong point there seeing as how it favors short wave UV?