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Beam stopper?

MajorLazor

MajorLazor

Member
Joined
Jun 5, 2019
Messages
46
Points
8
Wondering what you use to safely stop a beam? I'm getting a 2W PL-E mini from jetlasers, and am assuming it's not good to just have it pointed at a wall or something.
 





diachi said:
Beefy black anodized heatsinks work well too. The fins act as a bit of a baffle, helping contain any specular reflections.
Click to expand...

Something like this, maybe?

Amazon.com: URBEST Black Aluminum Heat Sink Heatsink for Three Phase Solid State Relay

Amazon.com: URBEST Black Aluminum Heat Sink Heatsink for Three Phase Solid State Relay
www.amazon.com

Or actually, this one might be better:

Amazon.com: Senmod 1pcs Black Aluminum Heatsink, Aluminium Heat Diffusion Cooling Fin 120 x 69 x 27mm/ 4.72"(L) x 2.72"(W) x 1.06"(H): Gateway

Buy Senmod 1pcs Black Aluminum Heatsink, Aluminium Heat Diffusion Cooling Fin 120 x 69 x 27mm/ 4.72"(L) x 2.72"(W) x 1.06"(H): Heatsinks - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
 
Last edited:
Or how about this?

Amazon.com: Avant Grub Grill Cleaning Brick. Commercial Grade Pumice Stone Tool Cleans & Sanitizes Restaurant Flat Top Grills or Griddles. Remove Grease Stains, Dirt and More Without Harsh Chemicals or Abrasives.: Gateway

Buy Avant Grub Grill Cleaning Brick. Commercial Grade Pumice Stone Tool Cleans & Sanitizes Restaurant Flat Top Grills or Griddles. Remove Grease Stains, Dirt and More Without Harsh Chemicals or Abrasives.: Grill Brushes - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
 
Hello,

what do you want?. Do you like to see the focused beam on a target or do you want to absorb all the light on the target? In this case I would suggest to use a black box with black velvet inside and a hole at the target side.


best regards

Edgar
 
reloader45 said:
Hello,

what do you want?. Do you like to see the focused beam on a target or do you want to absorb all the light on the target? In this case I would suggest to use a black box with black velvet inside and a hole at the target side.


best regards

Edgar
Click to expand...

If I have it set up on my desk for burning, I just want to have the beam terminate on something besides the wall. At what distance will a 2W 445 laser no longer burn things?
 
MajorLazor said:
If I have it set up on my desk for burning, I just want to have the beam terminate on something besides the wall. At what distance will a 2W 445 laser no longer burn things?
Click to expand...
Lol farther than the distance to any wall in your house.
Another solution would be to use a short negative focal length lens that will diverge the beam
 
I have many 2+ watt lasers that I can focus on any of my walls with no harm to the wall or any marks to show that this was done. I suppose it depends on the paint used, but a white wall won't absorb like a black item will so it is less likely that your wall would be damaged. White is more reflective than dark colors, especially black. Now, I would not try this with a 7 watt laser at a short distance because the power density of the beam is high at very short distances. The further out you get the safer this becomes as long as you haven't used optics that keep the divergence of the beam low. I have used lasers up to 4 watts against my white walls without harm of any kind.
 
steve001 said:
Lol farther than the distance to any wall in your house.
Another solution would be to use a short negative focal length lens that will diverge the beam
Click to expand...

I don't think it's a good idea to use any kind of glass beam stop not even a lens unless the whole system is bolted down, if it's not bolted down then it's a reflection hazard.
 
RedCowboy said:
I don't think it's a good idea to use any kind of glass beam stop not even a lens unless the whole system is bolted down, if it's not bolted down then it's a reflection hazard.
Click to expand...
Not 100% sure but I think what Steve had in mind was to focus the laser to as fine a point as possible for burning at a range of a few inches. Focused that way the beam would then diverge rapidly away from the 'work' area.
 
WizardG said:
Not 100% sure but I think what Steve had in mind was to focus the laser to as fine a point as possible for burning at a range of a few inches. Focused that way the beam would then diverge rapidly away from the 'work' area.
Click to expand...

That is what my green laser does now. The spot on the wall is probably 4-5" across when I have it focused close, but that laser is under 100 mW.
 
In order to burn anything with a <100 mW laser you need to focus the beam on your target about 2 to 3 inches away. That will give you a beam profile of less than 1 mm. You need that kind of power density to get a 75 mW laser to melt or burn anything. Of course the beam will diverge quickly past this focal point, so you needn't worry about a beam stop as the size of the dot at a couple of feet is quite large.
 
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