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FrozenGate by Avery

good "beam expander" alternatives?

Joined
Oct 2, 2008
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hi, i was wondering if there are some alternatives to the expensive beam expanders ($200-300).i heard that similar efects could be achieved with a te;escope or binoculars?
ideas?

thanks
 





FrothyChimp said:
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.

http://www.laserpointerforums.com/forums/YaBB.pl?num=1222253348

But I'm sure that's not cheap either.
 
There are many things you can use as a beam expander. I tried pointing my crappy 5mW red through some binoculars and it worked just fine, BUT i am not sure what a higher power laser would do to them.

I was thinking of using my telescope to give my laser some SERIOUS range. 8-)
Remember that the lasers beam will travel MUCH farther and could get you or someone into a LOT of trouble. ;)

--hydro15
 
DL beam expander seems to do the trick. It wasn't what I expected, but it's still cool none the less. Unfortunately I only have a lower power laser to work with it, so I can't say what it will be like when using 100mW+ green lasers, but it does the job. Beam comes out of the end really fat and just keeps getting smaller and smaller.

Best time I used it was in fog and when in those conditions, it's deffinately worth it. It goes from, bright at the laser head and faded at the end, to expanded at the laser head and pin point bright in the sky. Of course from that point in the sky, the divergence goes haywire. But as far as overall divergence goes from the laser head, it might as well be in the minus.

It's something I need to get a CNI pen for so I can get more out of it...
 
In all honesty just about any set of binoculars or telescope will work as a beam expander. Check out this video: http://www.youtube.com/watch?v=_9QotAtxrmc

The problem is usually finding out a way to properly mount and align it, which is why Laserglow made the X10DR, a custom beam expander attachment for the Aries and Hercules.
 
I just bought a 10X melles-groit for $110 on fleabay. I think I'm having more fun with the beam when its six feet across than then the pencil point.
 
I've tried binoculars before and that wasn't too effective sadly. I've tried a magnifying glass which did nothing. I'm guessing the cheapest method is to buy a telescope. I plan to buy a used one eventually the actual tools designed for a laser would be my choice but 250$ is a bit much. If it was only 50$ they would have deal.
 
laser83 said:
I've tried binoculars before and that wasn't too effective sadly. I've tried a magnifying glass which did nothing. I'm guessing the cheapest method is to buy a telescope. I plan to buy a used one eventually the actual tools designed for a laser would be my choice but 250$ is a bit much. If it was only 50$ they would have deal.

See post # 2
 
steve001 said:
[quote author=laser83 link=1222962978/0#11 date=1234491136]I've tried binoculars before and that wasn't too effective sadly. I've tried a magnifying glass which did nothing. I'm guessing the cheapest method is to buy a telescope. I plan to buy a used one eventually the actual tools designed for a laser would be my choice but 250$ is a bit much. If it was only 50$ they would have deal.

See post # 2[/quote]

The auction has closed. :'(
 


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