Old 12-20-2008, 05:51 PM #65
Class 2M Laser
 
Join Date: Sep 2007
Posts: 526
Rep Power: 13
disma is on a distinguished road
disma disma is offline
Class 2M Laser
 
Join Date: Sep 2007
Posts: 526
Rep Power: 13
disma is on a distinguished road
Default Re: My laser makes a red lit dot in thin air...

that is a possibility. I will try it after I get my 1w recharged tonight. 8-)



disma is offline   Reply With Quote


















Old 12-20-2008, 09:57 PM #66
Class 1M Laser
 
Join Date: Aug 2008
Posts: 181
Rep Power: 10
sad_sagi is on a distinguished road
sad_sagi sad_sagi is offline
Class 1M Laser
 
Join Date: Aug 2008
Posts: 181
Rep Power: 10
sad_sagi is on a distinguished road
Default Re: My laser makes a red lit dot in thin air...

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
sad_sagi is offline   Reply With Quote
Old 12-20-2008, 10:51 PM #67
artix's Avatar
Class 2M Laser
 
Join Date: May 2008
Posts: 994
Rep Power: 16
artix is a jewel in the roughartix is a jewel in the roughartix is a jewel in the roughartix is a jewel in the rough
artix artix is offline
Class 2M Laser
artix's Avatar
 
Join Date: May 2008
Posts: 994
Rep Power: 16
artix is a jewel in the roughartix is a jewel in the roughartix is a jewel in the roughartix is a jewel in the rough
Default Re: My laser makes a red lit dot in thin air...

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!
artix is offline   Reply With Quote
Old 12-22-2008, 04:17 PM #68
Lighhouse
Guest
 
Posts: n/a
Lighhouse
Guest
 
Posts: n/a
Default Re: My laser makes a red lit dot in thin air...

But, if it is plasma, is should (small amout of matter...) be cooling down very fast and the dot should dissapear
  Reply With Quote
Old 12-22-2008, 05:39 PM #69
Class 1M Laser
 
Join Date: Sep 2008
Posts: 182
Rep Power: 10
kernelpanic is on a distinguished road
kernelpanic kernelpanic is offline
Class 1M Laser
 
Join Date: Sep 2008
Posts: 182
Rep Power: 10
kernelpanic is on a distinguished road
Default Re: My laser makes a red lit dot in thin air...

Quote:
Originally Posted by Lighthouse
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
kernelpanic is offline   Reply With Quote
Old 12-22-2008, 09:28 PM #70
Class 2 Laser
 
Join Date: Jan 2008
Posts: 300
Rep Power: 455
360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute
Send a message via AIM to 360freak
360freak 360freak is offline
Class 2 Laser
 
Join Date: Jan 2008
Posts: 300
Rep Power: 455
360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute360freak has a reputation beyond repute
Send a message via AIM to 360freak
Default Re: My laser makes a red lit dot in thin air...

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.
360freak is offline   Reply With Quote
Old 12-22-2008, 09:29 PM #71
Class 1M Laser
 
Join Date: Dec 2008
Posts: 107
Rep Power: 10
Low-Q is on a distinguished road
Send a message via MSN to Low-Q
Low-Q Low-Q is offline
Class 1M Laser
 
Join Date: Dec 2008
Posts: 107
Rep Power: 10
Low-Q is on a distinguished road
Send a message via MSN to Low-Q
Default Re: My laser makes a red lit dot in thin air...

Quote:
Originally Posted by kernelpanic
[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
Low-Q is offline   Reply With Quote
Old 12-23-2008, 02:27 AM #72
Ref's Avatar
Ref Ref is offline
Class 1M Laser
 
Join Date: Nov 2007
Location: North Carolina
Posts: 178
Rep Power: 18
Ref is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to behold
Ref Ref is offline
Class 1M Laser
Ref's Avatar
 
Join Date: Nov 2007
Location: North Carolina
Posts: 178
Rep Power: 18
Ref is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to beholdRef is a splendid one to behold
Default Re: My laser makes a red lit dot in thin air...

Do you HAVE to turn your lens flat side out to recreate this? I want to try when my BR arrives, tomorrow. =D
__________________
532nm 30mW ('potted' to 50mW) DX Romisen L-C030
532nm >200mW S-KY PGL-200

445nm ~200mW Kryton Smooth, c/o daguin
Many 5mW greens and reds, one of those 70mW red modules in the Al heatsink from DX, etc..
Ref is offline   Reply With Quote
Old 12-23-2008, 07:17 AM #73
Class 1M Laser
 
Join Date: Dec 2008
Posts: 107
Rep Power: 10
Low-Q is on a distinguished road
Send a message via MSN to Low-Q
Low-Q Low-Q is offline
Class 1M Laser
 
Join Date: Dec 2008
Posts: 107
Rep Power: 10
Low-Q is on a distinguished road
Send a message via MSN to Low-Q
Default Re: My laser makes a red lit dot in thin air...

Quote:
Originally Posted by Ref
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
Low-Q is offline   Reply With Quote
Old 12-24-2008, 05:01 AM #74
Member
 
Join Date: Oct 2007
Posts: 37
Rep Power: 0
darmom is on a distinguished road
darmom darmom is offline
Member
 
Join Date: Oct 2007
Posts: 37
Rep Power: 0
darmom is on a distinguished road
Default Re: My laser makes a red lit dot in thin air...

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?
darmom is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

























Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 05:56 PM.


Powered by: vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC