Best material to diffuse light
Best material to diffuse light
(OP)
Hi everyone,
We are building a setup to distribute the light from LEDs to optical fibers. We have 3 LEDs (blue, red and green). They are connected to a plexiglass light mixer (with a in between LCD as a filter). On the other end we put optic fibers.
The plexiglass has a cross section of 18x18mm2 and it's 150mm long.
The problem we have is the light is not homogeneous on the fibers end so some fibers get more light than others.
The light mixer should be as short as possible.
Does anybody have recommendation for a better material for the mixer?
Attached a sketch showing the idea
thanks
http://files.engineering.com/getfile.aspx?folder=7...
We are building a setup to distribute the light from LEDs to optical fibers. We have 3 LEDs (blue, red and green). They are connected to a plexiglass light mixer (with a in between LCD as a filter). On the other end we put optic fibers.
The plexiglass has a cross section of 18x18mm2 and it's 150mm long.
The problem we have is the light is not homogeneous on the fibers end so some fibers get more light than others.
The light mixer should be as short as possible.
Does anybody have recommendation for a better material for the mixer?
Attached a sketch showing the idea
thanks
http://files.engineering.com/getfile.aspx?folder=7...





RE: Best material to diffuse light
TTFN
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RE: Best material to diffuse light
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Best material to diffuse light
thanks for the recommendation of this company. I have contacted them for a sample
MacGyverS2000,
sorry, it might be a language problem from my side. What do you mean with frost the interface? to de-polish? roughen the end face?
thanks
RE: Best material to diffuse light
Looks like IR beat me to the punch on the holographic diffuser.
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Best material to diffuse light
your idea is also good, we can try it quickly
thanks!
RE: Best material to diffuse light
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Best material to diffuse light
Surface diffusers tend to be somewhat Lambertian, so any standoff distance can drastically reduce the transmission efficiency. Some holographic diffusers are designed for specific exit cone angles,, which can greatly improve the overall efficiency.
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RE: Best material to diffuse light
nice explanation
how would you connect the rods? optical grease? optical-transparent glue? just pressing one against the other?
IRstuff,
Are the holographic diffuser always surfaces? Our setup will be placed in a non very well controlled area so I fell like a solid diffuser will be more stable
RE: Best material to diffuse light
Is this for a prototype or a production unit? I would definitely do things differently for each... what are you trying to create?
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Best material to diffuse light
We have some 500 crystals to be cured (from radiation) and calibrated (photosensors) with light. We have 3 LEDS (blue, green and red)and 4 fibers (200microns core diameter) per crystal.
We need to bring light from the LEDs to the crystals and we need to have the same light on each crystal.
For that we use this light mixer (here again the sketch)
http://files.engineering.com/download.aspx?folder=...
right now we have 15cm of plexiglass but the homogeneity is not good.
cheers,
RE: Best material to diffuse light
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Best material to diffuse light
The problem is finding the proper material/length for the homogeneous light at the end of the rod
I have found this:
http://www.edmundoptics.co.uk/optics/prisms/light-...
what do you think? looks more promising than plexiglass
cheers,
RE: Best material to diffuse light
I'm imagining something (relatively) simple... a cast piece of plastic in a triangular form with a dimple on each "point" to hold a few fibers each. The spacing of the triangle is the same as the spacing of the three LEDs in the cluster. The fibers are immediately pulled together into a bundle, or you could use a much smaller triangle that mixes a fiber from each color at each point, essentially homogenizing the colors there.
Of course, I was also assuming you were calibrating each crystal one at a time... if you have a need to do all 500, you'll need to figure out a way to efficiently route the fibers. But then again, you would have to do that anyway, regardless of what solution you used if it involved fiber.
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Best material to diffuse light
TTFN
I can do absolutely anything. I'm an expert!
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RE: Best material to diffuse light
We will have like 5 or 6 of these diffusers, so the cost is assumable.
About the fibers side; we also have to study it, but the first step is checking the homogeneity (for that we use the same fiber to be able to compare values from different points)
cheers,
RE: Best material to diffuse light
TTFN
I can do absolutely anything. I'm an expert!
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FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Best material to diffuse light
At its input end, it had a single port, ~6mm dia, that was aligned with a light source.
At the other end, ~50mm away, it had two similar smaller ports, spaced apart ~25mm.
In between was a forked bundle of optical fibers, 'randomized', and potted.
We never found out exactly how they randomized the fibers, but the output was sufficiently uniform for our purposes.
I see that Welch-Allyn has been acquired by Hill-Rom.
I do not know how that affects things; they were extraordinary partners for us.
Mike Halloran
Pembroke Pines, FL, USA