Tube glow from a 30mW Argon laser, is it safe to look at.

[Jem]

Cool paperweight Jem Does it lase?

Err... Well, yes and no

It was lasing before cleaning the brewster windows, now it need realigning, a task which I vastly underestimated the complexity of. Walking in a large argon is relatively easy, especially when your getting 100's of mW of light as a potential output. You get somewhere near with the alignment and get a 'flash'. From that point you know you're pretty close, a bit of final tweaking and you can increase the power. However, with my little beastie we're only talking around 0.5mW of output power at best, therefore no flash to look for.

I really need to get this onto a stable optical table and fire another HeNe down the bore. Once I can get the HR mirror set up I then only have the OC to deal with. Trying to walk in both mirrors without using the aforementioned technique has proved virtually impossible. It would be nice to get 'her' lasing again but it's not the end of the world as just watching the plasma glow is enough of a turn on when i'm in the office

Cheers

Jem

[Psi]

Be sure the acrylic (or Polycarbonate/Lexan) you use can handle the heat from the tube. Especially acrylic has a fairly low melting point, so it may turn soft because of the tube's heat production.

Yeah, i've already had a look at that.
I ran the laser for 10minutes and checked the temps all round the case.
It was barely warm, even the air coming out of the fan isn't that hot. Just very warm.

[DanBarlow]

You can test the UV pass of your mystery sheet with some glow-in-the-dark or fluorescent material.

[Psi]

You can test the UV pass of your mystery sheet with some glow-in-the-dark or fluorescent material.

yeah, i tried that with some ultrabright UV leds and a glow in the dark object.
I couldn't notice any difference with/without the sheet.

I suspect the visible output from the UV led is overpowering the UV output.
I really need a filter to pass only UV in front of the led or a UV led that doesnt output visible light.
That way only the UV gets (or doesn't get) to the glow in the dark object thought the sheet.

[Xytrell]

Does nobody know what type of glass is in the laser?

You can test the UV pass of your mystery sheet with some glow-in-the-dark or fluorescent material.

Not really. Blue and violet will "charge" glow-in-the-dark material almost as well as UV.

yeah, i tried that with some ultrabright UV leds

The "UV" leds I've tested are generally closer to 405 or 410nm.

[mixedgas]

`The tube is made of Schott's Pyrex compatable Kovar sealing glass, type 8250. I'm 100% sure of that, or the equalvalent Sumitomo product.

DO NOT ask how I know that.....

Oh wait, I know what Kovar is.... Thats how I know, (yeah right, I have my sources..., and have read the NEC patents, long ago)

Pyrex transmits considerable UV.

The normal lid on a NEC is 1/16th inch aluminum, painted with some sort of insulating thick black paint to prevent arcs.

You need some polycarbonate plastic between you and the tube.

Steve

Steve