Terminate a beam

[Mille]

What's a good way to terminate a beam?
So the beam is visible and the spot is absorbed and dont make reflections.

 

[Cyparagon]

I'm not sure if beams are his specialty, per se. He might charge extra.

 

[Murudai]

Anything black, essentially

(^ He's got black on him... so... who knows)

 

[Mille]

Yes something black, but i dont think it absorb the radiation completely.
Any hint to build something to have the smallest dot possible?

The terminator without skin could be dangerous with lasers

 

[Maven]

i would try like black cloth or felt.. or build a little box and line the inside with black cloth and only a small hole going in.. that way nothing gets back out.. but second idea wont work if you are trying to see the dot.

 

[rangedunits]

PSB Cubes =)

 

[RA_pierce]

Get a small box, paint the inside black, and a metallic surface that will reflect the beam, but spread it out at the same time (something like a shiny quarter). It must be something that will not reflect the beam back toward the laser. It may help if you color the reflective surface black with a sharpie or something to increase the amount of absorbed light.
Position it at an angle in the box so that the reflection is directed toward a blank wall in the box.
The beam will reflect off the quarter (or whatever you use) and be diffused, making it easier for the inside of the box to absorb the light. Also, since the beam is spread out, it won't burn or melt holes in your box!
Make sure the entire thing is closed off except for the hole the beam is supposed to enter.

 

[VillageIdiot]

I was thinking of something similar except I had the idea of drilling a hole in something and putting some sort of glazed glass in the way.

 

[Mille]

Ok thanks for answers

The box with the mirror seems a good solution.

 

[VillageIdiot]

Not a mirror. It has to diffuse it as well or it doesn't work.

 

[GooeyGus]

Cutting wheels!!! The kind used on a die grinder or dremel for cutting metal.

Climbak used these to terminate his .5W green labby. When you think about it, they're perfect.

They are usually black, and designed to take a lot of heat. Climbak used a setup similar to the box/diffuser design, except he bounced the beam off of a mirror onto a pile of crushed up cutting wheels. Works like a champ!

 

[VillageIdiot]

Why cutting wheels? Why not just rocks... how much heat can a diffused laser give out anyways?

 

[GooeyGus]

Why cutting wheels? Why not just rocks... how much heat can a diffused laser give out anyways?

Well, in climbak's case the beam wasn't diffused, he just bounced it off a mirror and onto the wheels.

The reason why the wheels are nice vs. rocks is because they are lightweight, and flat. The flatness helps if you're trying to view the actual dot. Where a rock may warp the dot, the flat surface of the grinding wheel should keep it pretty uniform. Not to mention a shiny rock could cause some reflections.

 

[VillageIdiot]

I'm sorry, it's too late and I'm too tired to process logic and reason so here's a picture of a happy snake.

 

[FrankenPC]

You can use a tungsten screen. Hit it with the smoke from a candle to give it some carbon black. The tungsten won't melt. It has a lot of advantages. I think it's used as a beam dump for CO2 lasers.

 

[Omega]

im going to ask a potentially dumb question.
why do you need to "terminate" said beam?