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

[disma]

that is a possibility. I will try it after I get my 1w recharged tonight.

 

[sad_sagi]

yeah i worry about whats in the tip of the cheapo marker i used.

oh and a black pencil (like a colored pencil) worked too. normal pencil worked once even.

very strange.

my poor dilda heats up too fast... lol

if its easier with a blu, then i'm gonna have to get one lol

 

[artix]

I just tried it with the paper/cardboard package of Energizer batteries and it worked! It didn't last nearly as long but it worked!

 

[Lighhouse]

But, if it is plasma, is should (small amout of matter...) be cooling down very fast and the dot should dissapear

 

[kernelpanic]

But, if it is plasma, is should (small amout of matter...) be cooling down very fast and the dot should dissapear

As dar303 pointed out, there is no plasma. The effect is produced by optical trapping. Basically, the coherent light, when converging tight enough (i.e. when focused close) will hold small particles just past the focus point of the beam. With practice I've been able to keep the particles stuck there for quite some time. On a hobby scale, the effect isn't 'useful'. But I can think of a bar-bet scenario in which it could be put to good use...

cheers,
kernelpanic

 

[360freak]

I'm guessing that the blu ray does a better job since it can get down to a much shorter focal point, and the photons/packets are much stronger overall at that wavelength.

 

[Low-Q]

[quote author=Lighthouse link=1229287299/60#67 date=1229962674]But, if it is plasma, is should (small amout of matter...) be cooling down very fast and the dot should dissapear

As dar303 pointed out, there is no plasma. The effect is produced by optical trapping. Basically, the coherent light, when converging tight enough (i.e. when focused close) will hold small particles just past the focus point of the beam. With practice I've been able to keep the particles stuck there for quite some time. On a hobby scale, the effect isn't 'useful'. But I can think of a bar-bet scenario in which it could be put to good use...

cheers,
kernelpanic[/quote]Is anything with this laser-matter-burning-playaraund-starwars-optical-trapping-thing we are doing, useful at all? ;D

Low-Q

 

[Ref]

Do you HAVE to turn your lens flat side out to recreate this? I want to try when my BR arrives, tomorrow. =D

 

[Low-Q]

Do you HAVE to turn your lens flat side out to recreate this? I want to try when my BR arrives, tomorrow. =D

Hi,

if you wanna recreate a perfect image of the projected laser from the laser chip, you must do exactly the oposite of the lens #1 which has its focal point at the laser chip.
If you have studied the two tiny lenses on 808nm diodes which is focused on the Yag chrystal, these two tiny lenses are equal, but mounted in oposite direction to make the 808nm point at the chrystal as small and intense as possible.

However, if your laser is powerful enough, I bet the direction of the focus lens isn't that critical. You will probably have a distorted focal point which has a certain distance where the beam are at its smallest diameter. Then it would probably be harder to get a stable and "fixed" trap.

br.

Vidar

 

[darmom]

Part of the explanation was that it works best with lower powers... has anyone tried using a regular flame to burn the item, thereby creating the trappable particles, and then a lower power, focused laser to trap them? It might allow the particles to remain trapped longer because they won't be subjected to the high heat of a powerful beam. This might explain the inability to recreate this process with a 998mw beam.

thoughts?