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ArcticMyst Security by Avery

10ish way beam splitter

Joined
Dec 23, 2012
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Anyone know an inexpensive 10ish way beam splitter to which I can attach PMMA fiber optic lines?

I wear about 8-10 red lasers with line diffraction gratings at events like Burning Man. I want to replace my current setup with one based on fiber optics for various reasons :
- 5mW red lasers are dirt cheap, but 10 blue lasers is way too expensive.
- the wires break frequently get broken off my laser modules.
- laser modules are too big to sit, pass out, sleep, etc. on comfortably.

The beam splitter should be small and light weight, but doesn't need to be particularly good quality. I just need the beam coming out the other end of the fiber optics to still be a beam.

I'm also looking for a cheap, small, and sturdy method to attach diffraction gratings to the ends of the fiber optic lines too, maybe just hot glue will work if I carefully avoid the light's path.
 





Joined
Dec 29, 2009
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Not it!

1st, not safe.
2nd, dangerous.
3rd, very hazardous!
4th, people may punch you or throw sand in your face
5th, not safe.


with that said, put the pipe down and think about how to get light from one laser, whose light comes out in a 3x3mm beam, into 10 strands of fiber, each one with diameter much smaller than 1mm.

Ok, putting down the spoon of strained peas now.
 
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Joined
Sep 12, 2007
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I just need the beam coming out the other end of the fiber optics to still be a beam.

That's not how fiber optics work. You need a lens assembly on either end to launch and collimate it. These aren't particularly cheap, nor are they resilient to the abuse you'll certainly put them through. Fibers are arguably more fragile than standard wire. If your wire is breaking a lot, you'll be even more disappointed when your pricey fiber goes to shit.

Stick to your reds. Reinforce the areas that break.
 
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Joined
Aug 14, 2013
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I agree. Try using headphone wires as they are designed for abuse and flexing. The strands of copper
in them are very thin. Also, look up strain relief. You need strain relief where the wires enter the
modules. Tie a knot in the wire inside the module as well so that pulling on the wire puts pressure on
the knot and not on the solder points. Also, since this will be shining in peoples' eyes, go for under
1mW. 5mW is still not good when shone directly into the eye. Absolutely do not use green lasers
because they tend to put out more power than their rating. Probably best to avoid blue as well since
low power blues are less common.
 
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Mar 27, 2013
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Most blues easily output 200mW... very difficult to find a 5mW blue. I agree^
 
Joined
Dec 23, 2012
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Alright, thanks guys! No lasers though fiber options then. :)

I also bought smaller reds that (a) expose the solder points on a circuit board and (b) cannot easily mount a diffraction grating.
2~5mW Dot Red Laser Module (5-Pack/3V) - Free Shipping - DealExtreme

If I found a way to mount a diffraction grating, maybe just careful gluing, then I could repair them easier, assuming I only break off the wires, not breaking the board. And they're dirt cheap as fuck if I break the boards off, actually the diffraction cost more.

Another idea for blue laser is buying 10ish cheap blue laser pointers
Hot Sale+Wholesale Price 1pcs/lot High Power Light Beam Blue Laser Pointer Pen Free Shipping 750007-in Laser Pens from Consumer Electronics on Aliexpress.com

I'd need to attach diffraction gratings somehow and modify them for rechargeable batteries. I'd imagine these each use three watch batteries, which basically do not exist as rechargeables. If however those watch batteries output around 3-4V then I could maybe modify them to use a single AAA Li-ion battery, which outputs around 3.6V. These would be even more uncomfortable to wear than my current setup, but hey.

Any thoughts on either approach?

Thanks again,
Jeff

p.s. Anyone seen cross diffraction gratings with a 90 degree or larger angle? I've line diffraction gratings with at least a 90 degree angle, but the crosses I've bought all have more like a 60degree angle.
 
Joined
Dec 23, 2012
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Alright, thanks. I'll try placing small springs around the leads on the next few, see if they hold up better.

Any idea about cross diffraction gratings with beam angles larger than 90 degrees?
 
Joined
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What do you mean by "larger than 90 degrees"? I don't think it's even possible to get a 90° diffraction
angle even in the nth order. You can reflect upward with a mirror grating, but that's not the same thing
as a diffraction angle.
 
Joined
Dec 23, 2012
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Oops, I meant wider than 60 degree wherever I said 90 degree, sorry. Actually these lenses go up to 120 degrees :
5pcs 120° Line Tips/Len for Laser Module Housing (1230) M9*0.5

But my problem with using crosses instead of lines is that all the crosses I've seen only do 60 degrees.

In fact, I've just found a 110 degree cross lens here :
Optic Cylinder Glass Cross Lens 110 °
which is exactly what I'm looking for. I swear that wasn't there before! :)

I'll see if I can find a Chinese and/or bulk supplier for that lens, definitely not paying $6 per lens. lol
 
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Dec 23, 2012
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