Need IR Laser to burn paper from 5-300feet

[ArdvarkOfDoom]

Get a tri-pod and a good laser... set it up behind the paper, but far enough "off stage" to not be noticeable (or build an enclosure that just happens to have a hole in it and put it right next to the paper)... and get a wireless remote to fire the beam? Something like that with <5 ft range seems to work better than trying to deal with all the problems of 300 ft.

 

[GooeyGus]

Get a tri-pod and a good laser... set it up behind the paper, but far enough "off stage" to not be noticeable (or build an enclosure that just happens to have a hole in it and put it right next to the paper)... and get a wireless remote to fire the beam?  Something like that with <5 ft range seems to work better than trying to deal with all the problems of 300 ft.

Thats what I had envisioned as well

 

[asalada]

You know what I use for long distance beam collimation? A shooters spotting scope. The optics tend to be broadband AR coated (for decent scopes anyway). Fire the laser though the eye piece and out comes a very wide beam with very little divergence. Using the focus on the scope as well as the zoom on the scope makes it pretty easy to fire 100m.

The issue I see, well besides the inherent safety issue, is that inexpensive IR lasers are diode based which means you use multimode diodes to generate the high powers with beam quality M2 of like 20. This makes it very hard to focus the beam to a fine point, and even more difficult to focus when expanded. The solution is a diode pumped YAG or YVO4 outputting 1064nm. The beam quality at that point is <2.0 but they cost much more.

If i need to aim the 1064nm, will i be able to use a camera to see the IR light?
how far will i be able to burn white paper using 1W IR?
I came across portable IR laser from huanic & sky, are they up to do the job?

 

[FrothyChimp]

Most video cameras can see the 1064nm dot. I know my Sony can.