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FrozenGate by Avery

My laser makes a red lit dot in thin air...

L

Low-Q

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Dec 14, 2008
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Hi. I have a 635nm laser from a 16x DVD burner. When I focus this laser on a plastic piece, a red lit small dot remains in thin air for as long as the laser is activated - somtimes shorter time. So I wonder if someone knows what is happening. Is it plasma from platic vapour, or what is it?

I'm not allowed to post links here yet, but on youtube you can paste in these two lines at "YouTube dot com slash" to find the videos:

watch?v=9AzdMJSvuUU&NR=1

and

watch?v=ig_L3PnSuo0

br.

Low-Q
 





looks like a bit of smoke or something stuck in the air, my blu-ray did that when I burned a piece of rubber right in front of it
 
Thanks for the reply.
It is funny, because if I move the laser sideways, up side down, horizontal, whatever, the small lit dot seems to get stucked in the focus point. I could see this red dot lit for almost two minutes stright. Could that still be remaining vapour after that long time? if you look at the first video, you can in the middle and at the end of the video see a spark that gets off the dot at the same time as the dot gets less lit. So it seems to me that the dot is of some unstable matter that is releasing some of its mass.

br.

Low-Q
 
Hmm...

I can't say I've seen that before... Really strange phenomenon... Looks like plasma...

Normally all I see at the focal point is the speckling of dust in the beam.. It looks like a glittery cone, not a fixed point like that. Does that only happen after you've burnt something with it? Can you feel any heat radiating from the dot? Can you blow it out?

links for the lazy:
http://www.youtube.com/watch?v=9AzdMJSvuUU&NR=1
http://www.youtube.com/watch?ig_L3PnSuo0
 
john_lawson said:
unauthorized site web restricted crap work filter  :'(
Click to expand...
try https://ctunnel.com

it's the easiest and most surefire method I know.. otherwise here's a huge list of different things you can try:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1211141875#10

But back on topic, has anyone else seen this before or can offer an explanation? I hear bluray can ionize air at high powers, but red seems far to long a wavelength for this to happen... It really looks like it could be some sort of plasma... Like ball lightning or something.
 
I just tried this with the dilda and it works! Looks awesome, great discovery. No idea what it is or why it happens, maybe it's fusion, lol xD.

What exactly did you burn? I only got it to work with esd-foam and it only worked for 10-20 seconds at best.
 
pseudolobster said:
Hmm...

I can't say I've seen that before... Really strange phenomenon... Looks like plasma...

Normally all I see at the focal point is the speckling of dust in the beam.. It looks like a glittery cone, not a fixed point like that. Does that only happen after you've burnt something with it? Can you feel any heat radiating from the dot? Can you blow it out?

links for the lazy:
***I had to delet these links to post - Low-Q***
Click to expand...

It is possible to blow it out, but a gentle breeze like when i move the laser sideways through the air, the dot is in fixed position. I cannot feel heat from it.
 
FireMyLaser said:
I just tried this with the dilda and it works! Looks awesome, great discovery. No idea what it is or why it happens, maybe it's fusion, lol xD.

What exactly did you burn? I only got it to work with esd-foam and it only worked for 10-20 seconds at best.
Click to expand...
Hi,

I burned a felt pen... I guess you can see the sort of pen in one of the videos. Look at the name on it: "Jumbo Highlighter" ;D Not strange it works that well..he-he
Anyway, it is for me a new discovery - a quite nice one too :)


Low-Q
 
I see he-he. Strange that I haven't seen this on youtube or in other sites before! I mean, there is plenty of geeks like me out there burning stuff with lasers.

i still look for an explanation - if anyone have a good theory of what it is.

I can add this information: The beam seems not to be disturbed, or blocked by this dot as a projection on the celing or the wall doesn't change when I blow this dot out. So it is possibly a transparent matter of some sort - maybe overheated air which is refracting small portions of the light.
The dot is also most visible when i look towards the laser apperture (Not directly into the laser beam ofcourse). If I point the laser away from me this dot seems weaker. That can tell me that the light in this dot is mainly going in one direction - away from the laser apperture as the rest of the light - hence no visible disturbance of the projection on the wall.

Any thaughts about this?

Low-Q
 
the only thing I can think of is that the laser heats up the plastic and the air around it and starts ionizing the air, and when you take it away the ionization continues.

thats my theory anyway.

-Adam
 
Maybe a silly question: does it work if the laser is aimed downward onto the plastic, instead of upward? Both videos show it being upward, at least that's what they appear to show.
 
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