(plastic) optical fibre

[kristoff]

Hi,


I want to learn a more and experiment with optical fibre, especially for
communication.

Does somebody here have any experience with this (at a hobbyist level)?
There seams to exist a kit called FO-30K, that just uses LEDs,
optotransistors and plastic fibre. So it looks like this is a technology
for hobbyies to play with.


Concering fibre, I found something called "POF" (plastic optical fibre),
which seams to be a lot easier to handle then glass fibre, and -hence- a
good start.
What would be a good thickness of fibre to start with? I found
references starting from epef-1 (1 mm core, 2.2 mm in total) to epef-18
(18 mm core).
Anybody any idea on what is easy to handle?


On the well-known Chinese webshops, I can buy cable in one batch of
(say) 10 meter.
Can you just cut the fibre at the length I need, or do you need special
tools for that?
(I know that glass-fibre must be cut in a certain angle to be well
terminated. I have no idea if this also applies to plastic fibre.


On the FO-30K kit, the holders on which to connect the ends fibre are
just metal rings.
Would it be possible to 3D print a connector for a transmittor and
receiver for an plastic optical cable?
Perhaps a two part housing: one that holds the LED/phototransistor and
one for (the end of) the fibre?



Any help or ideas would be appriciated.


Cheerio! Kr. Bonne. (ON1ARF)

 

[Tom Biasi]

On 4/8/2018 8:05 AM, kristoff wrote:

Hi,


I want to learn a more and experiment with optical fibre, especially for
communication.

Does somebody here have any experience with this (at a hobbyist level)?
There seams to exist a kit called FO-30K, that just uses LEDs,
optotransistors and plastic fibre. So it looks like this is a technology
for hobbyies to play with.


Concering fibre, I found something called "POF" (plastic optical fibre),
which seams to be a lot easier to handle then glass fibre, and -hence- a
good start.
What would be a good thickness of fibre to start with? I found
references starting from epef-1 (1 mm core, 2.2 mm in total) to epef-18
(18 mm core).
Anybody any idea on what is easy to handle?


On the well-known Chinese webshops, I can buy cable in one batch of
(say) 10 meter.
Can you just cut the fibre at the length I need, or do you need special
tools for that?
(I know that glass-fibre must be cut in a certain angle to be well
terminated. I have no idea if this also applies to plastic fibre.


On the FO-30K kit, the holders on which to connect the ends fibre are
just metal rings.
Would it be possible to 3D print a connector for a transmittor and
receiver for an plastic optical cable?
Perhaps a two part housing: one that holds the LED/phototransistor and
one for (the end of) the fibre?



Any help or ideas would be appriciated.


Cheerio! Kr. Bonne. (ON1ARF)

The kit will provide you with some useful experience but it's a little
"old school" The plastic cable has high loss but for educational
purposes it will serve fine. If you cut the cable it should be
perpendicular and will probably need to be polished.

 

[kristoff]

Hi Tom,

On 08-04-18 21:15, Tom Biasi wrote:

I want to learn a more and experiment with optical fibre, especially
for communication.

Does somebody here have any experience with this (at a hobbyist
level)? There seams to exist a kit called FO-30K, that just uses LEDs,
optotransistors and plastic fibre. So it looks like this is a
technology for hobbyies to play with.
The kit will provide you with some useful experience but it's a little
"old school" The plastic cable has high loss but for educational
purposes it will serve fine. If you cut the cable it should be
perpendicular and will probably need to be polished.

I am not interested in buying that particular kit. I have more then
sufficient electronic components laying around for this .. except for
the optical fibres themselfs.

My goal is to replicate the functionality of the kit myself, .. hence my
questions on the fibres themselfs and on how to make an interface from /
to a receiver / transmitter.


Kristoff

 

[Ecnerwal]

In article <pad0ii$82d$1@dont-email.me>, kristoff <kristoff@skypro.be>
wrote:

Hi,


I want to learn a more and experiment with optical fibre, especially for
communication.

Does somebody here have any experience with this (at a hobbyist level)?
There seams to exist a kit called FO-30K, that just uses LEDs,
optotransistors and plastic fibre. So it looks like this is a technology
for hobbyies to play with.


Concering fibre, I found something called "POF" (plastic optical fibre),
which seams to be a lot easier to handle then glass fibre, and -hence- a
good start.
What would be a good thickness of fibre to start with? I found
references starting from epef-1 (1 mm core, 2.2 mm in total) to epef-18
(18 mm core).
Anybody any idea on what is easy to handle?


On the well-known Chinese webshops, I can buy cable in one batch of
(say) 10 meter.
Can you just cut the fibre at the length I need, or do you need special
tools for that?
(I know that glass-fibre must be cut in a certain angle to be well
terminated. I have no idea if this also applies to plastic fibre.


On the FO-30K kit, the holders on which to connect the ends fibre are
just metal rings.
Would it be possible to 3D print a connector for a transmittor and
receiver for an plastic optical cable?
Perhaps a two part housing: one that holds the LED/phototransistor and
one for (the end of) the fibre?



Any help or ideas would be appriciated.


Cheerio! Kr. Bonne. (ON1ARF)

Plastic fiber is very limited, (both data rate and distance) but if
those limits match what you need to (want to) do, fine. If your interest
extends beyond "within room" or "room to nearby room" you might want to
skip it and start learning glass fiber.

IIRC (it's been a long time since I touched the stuff) you can basically
just cut it, but results may be improved by a polishing process of some
sort.

To give an idea of just how crude things can be and work, on a TOSLink
(audio, probably the most common application of POF in the consumer
space, if the junky lights are not in fashion) I have connected a normal
TOSLink cable to a "combined headphone jack and optical out" port by
sticking in a section of ball-point pen plastic (from behind/above the
ink) to activate the port in optical mode and serve as a crude coupler
to the tip of the TOSLink cable.

So I can't see any reason you could not print a connector. Or drill a
hole in the end of an LED and epoxy the fiber in, if you don't need a
dismountable connector, source-side.

Terminating glass fiber is a bit more complex than cutting it at any
particular angle, though that complexity may be hidden if using
mechanical-splice connectors.

The vast majority of POF I have seen in the wild is 1000um (1mm) core.
1.8mm would get you more light, but with even greater degradation in
distance and data rates due to the larger core having even more modes
(leading to different optical path lengths and thus transit times, so
pulses get "fuzzy.")

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

 

[whit3rd]

On Sunday, April 8, 2018 at 5:05:42 AM UTC-7, kristoff wrote:

I want to learn a more and experiment with optical fibre, especially for
communication.

Does somebody here have any experience with this (at a hobbyist level)?
There seams to exist a kit called FO-30K, that just uses LEDs,

A friend did instruction on this, and the support for plastic fiber and
LEDs is very poor (and laser coupled to single-mode fiber is both
commonly available, and higher performance in every respect).

What would be a good thickness of fibre to start with? I found
references starting from epef-1 (1 mm core, 2.2 mm in total) to epef-18
(18 mm core).
Anybody any idea on what is easy to handle?

Choose a wavelength, and a connector, and you can get transmitters and/or
receivers, or SFP transceiver modules, ready to connect.
A variety of suppliers stock cables, and semicustom build-to-order
cables, with the length and connectors you specify.

If you want to 'handle' making fiber connections, it takes a field splice kit
to cut and polish a fiber, and cement/crimp it into a suitable connector ferrule.
These exist, but are not much of a 'learning' experience for a communication
project. A few-miles reel of multifiber cable is how the real world
handles these fibers, and that's not gonna fit a student workbench.

 

[Jasen Betts]

On 2018-04-08, kristoff <kristoff@skypro.be> wrote:

I am not interested in buying that particular kit. I have more then
sufficient electronic components laying around for this .. except for
the optical fibres themselfs.

Use an optical SPDIF cable.

--
ŘŞ

 

[George Herold]

On Sunday, April 8, 2018 at 8:05:42 AM UTC-4, kristoff wrote:

Hi,


I want to learn a more and experiment with optical fibre, especially for
communication.

Does somebody here have any experience with this (at a hobbyist level)?
There seams to exist a kit called FO-30K, that just uses LEDs,
optotransistors and plastic fibre. So it looks like this is a technology
for hobbyies to play with.


Concering fibre, I found something called "POF" (plastic optical fibre),
which seams to be a lot easier to handle then glass fibre, and -hence- a
good start.
What would be a good thickness of fibre to start with? I found
references starting from epef-1 (1 mm core, 2.2 mm in total) to epef-18
(18 mm core).
Anybody any idea on what is easy to handle?


On the well-known Chinese webshops, I can buy cable in one batch of
(say) 10 meter.
Can you just cut the fibre at the length I need, or do you need special
tools for that?
(I know that glass-fibre must be cut in a certain angle to be well
terminated. I have no idea if this also applies to plastic fibre.

I know nothing about special angles. But years ago we'd make our own fibers
for sending/ receiving light down into cryostats. We'd nick the fiber with
a diamond scribe and then cleave it. (Break... there must be youtube videos
it's not at all hard.) The nick leaves a little section of the fiber
that is not perfect, but that didn't bother us.. A few percent of the area
was lost.

Your big job will be the optics to couple into the fiber. We had a lens,
fiber holder, x-y-z translation stage, and tip/tilt on the fiber holder.
... spendy.

George H.

On the FO-30K kit, the holders on which to connect the ends fibre are
just metal rings.
Would it be possible to 3D print a connector for a transmittor and
receiver for an plastic optical cable?
Perhaps a two part housing: one that holds the LED/phototransistor and
one for (the end of) the fibre?



Any help or ideas would be appriciated.


Cheerio! Kr. Bonne. (ON1ARF)

 

[John Larkin]

On Sun, 8 Apr 2018 14:05:37 +0200, kristoff <kristoff@skypro.be>
wrote:

Hi,


I want to learn a more and experiment with optical fibre, especially for
communication.

Does somebody here have any experience with this (at a hobbyist level)?
There seams to exist a kit called FO-30K, that just uses LEDs,
optotransistors and plastic fibre. So it looks like this is a technology
for hobbyies to play with.


Concering fibre, I found something called "POF" (plastic optical fibre),
which seams to be a lot easier to handle then glass fibre, and -hence- a
good start.
What would be a good thickness of fibre to start with? I found
references starting from epef-1 (1 mm core, 2.2 mm in total) to epef-18
(18 mm core).
Anybody any idea on what is easy to handle?


On the well-known Chinese webshops, I can buy cable in one batch of
(say) 10 meter.
Can you just cut the fibre at the length I need, or do you need special
tools for that?
(I know that glass-fibre must be cut in a certain angle to be well
terminated. I have no idea if this also applies to plastic fibre.


On the FO-30K kit, the holders on which to connect the ends fibre are
just metal rings.
Would it be possible to 3D print a connector for a transmittor and
receiver for an plastic optical cable?
Perhaps a two part housing: one that holds the LED/phototransistor and
one for (the end of) the fibre?



Any help or ideas would be appriciated.


Cheerio! Kr. Bonne. (ON1ARF)

Multimode glass fiber cables are cheap, connectorized ST or FC.

https://www.amazon.com/Tripp-Lite-Duplex-Multimode-N302-010/dp/B000067SC9/ref=sr_1_20?ie=UTF8&qid=1523335517&sr=8-20&keywords=st+fiber+patch+cable

Matching connectorized lasers and photodiodes are also cheap.

APC (angle polished connectors) are not needed for most applications;
they reduce back reflections a bit, which can matter in very high
speed, long run situations with lots of splices. Don't bother.

Plastic fiber has very high attenuation with distance. But the fibers
are big, so alignment is easy if you want to cut and terminate fiber
yourself. Most people buy glass fiber (62 or 9 micron core diameter)
already connectorized.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Phil Hobbs]

On 04/10/18 00:54, John Larkin wrote:

On Sun, 8 Apr 2018 14:05:37 +0200, kristoff <kristoff@skypro.be
wrote:

Hi,


I want to learn a more and experiment with optical fibre, especially for
communication.

Does somebody here have any experience with this (at a hobbyist level)?
There seams to exist a kit called FO-30K, that just uses LEDs,
optotransistors and plastic fibre. So it looks like this is a technology
for hobbyies to play with.


Concering fibre, I found something called "POF" (plastic optical fibre),
which seams to be a lot easier to handle then glass fibre, and -hence- a
good start.
What would be a good thickness of fibre to start with? I found
references starting from epef-1 (1 mm core, 2.2 mm in total) to epef-18
(18 mm core).
Anybody any idea on what is easy to handle?


On the well-known Chinese webshops, I can buy cable in one batch of
(say) 10 meter.
Can you just cut the fibre at the length I need, or do you need special
tools for that?
(I know that glass-fibre must be cut in a certain angle to be well
terminated. I have no idea if this also applies to plastic fibre.


On the FO-30K kit, the holders on which to connect the ends fibre are
just metal rings.
Would it be possible to 3D print a connector for a transmittor and
receiver for an plastic optical cable?
Perhaps a two part housing: one that holds the LED/phototransistor and
one for (the end of) the fibre?



Any help or ideas would be appriciated.


Cheerio! Kr. Bonne. (ON1ARF)

Multimode glass fiber cables are cheap, connectorized ST or FC.

https://www.amazon.com/Tripp-Lite-Duplex-Multimode-N302-010/dp/B000067SC9/ref=sr_1_20?ie=UTF8&qid=1523335517&sr=8-20&keywords=st+fiber+patch+cable

Matching connectorized lasers and photodiodes are also cheap.

APC (angle polished connectors) are not needed for most applications;
they reduce back reflections a bit, which can matter in very high
speed, long run situations with lots of splices. Don't bother.

Plastic fiber has very high attenuation with distance. But the fibers
are big, so alignment is easy if you want to cut and terminate fiber
yourself. Most people buy glass fiber (62 or 9 micron core diameter)
already connectorized.

POF can be cut with flush cutters and then polished. Various people
sell kits for that.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[kristoff]

Hi,

First of all, thanks all for the replies. It's great to see all these
replies.


(inline comments)


On 08-04-18 21:41, Ecnerwal wrote:

Plastic fiber is very limited, (both data rate and distance) but if
those limits match what you need to (want to) do, fine. If your interest
extends beyond "within room" or "room to nearby room" you might want to
skip it and start learning glass fiber.

Well, to put things into perspective, my motivation here is not to
actually use this. It is to learn.

So it doesn't matter is isn't optimal. (If it is just "plug an play",
there isn't much fun about it, no?)


I have been looking at this kit and also at the hardware used by ronja
(a free-space optics project), on how to interface the optical part with
the electronics.
First step is to get something working (basic on-off switching or analog
signals) and then try to interface the receiver with a high-speed DAC
and an FPGA or so and work from there on.


But that is for in the future. First things first.

IIRC (it's been a long time since I touched the stuff) you can basically
just cut it, but results may be improved by a polishing process of some
sort.

I didn't know you can polish plastic fibres too. That's interesting.

I'll give it a try.

To give an idea of just how crude things can be and work, on a TOSLink
(audio, probably the most common application of POF in the consumer
space, if the junky lights are not in fashion) I have connected a normal
TOSLink cable to a "combined headphone jack and optical out" port by
sticking in a section of ball-point pen plastic (from behind/above the
ink) to activate the port in optical mode and serve as a crude coupler
to the tip of the TOSLink cable.
That's a nice hack. - Very interesting!

Is TOSlink LED or laser based?

So I can't see any reason you could not print a connector. Or drill a
hole in the end of an LED and epoxy the fiber in, if you don't need a
dismountable connector, source-side.

Terminating glass fiber is a bit more complex than cutting it at any
particular angle, though that complexity may be hidden if using
mechanical-splice connectors.

OK, I understand that.

But my motto has always been to first learn how to crawl, and then walk.
I'll put glass-fibre on my "to do" list.

The vast majority of POF I have seen in the wild is 1000um (1mm) core.
1.8mm would get you more light, but with even greater degradation in
distance and data rates due to the larger core having even more modes
(leading to different optical path lengths and thus transit times, so
pulses get "fuzzy.")

In the mean time, I found a reference for 20 meter of 1 mm POF cable and
I'll start with that.

But it's a good idea to experiment with thicker POF later on. I
understand that the thicker core and the additional modes will "smear
out" the signal more.


Cheerio! Kr. Bonne.

 

[kristoff]

Phil, (and all others),



On 10-04-18 15:00, Phil Hobbs wrote:

POF can be cut with flush cutters and then polished.  Various people
sell kits for that.

Thanks!


I'll do a little more research on how to do polish a POF and try it out!

Cheers
Phil Hobbs

Cheerio! Kr. Bonne.

 

[Jasen Betts]

On 2018-04-10, kristoff <kristoff@skypro.be> wrote:

IIRC (it's been a long time since I touched the stuff) you can basically
just cut it, but results may be improved by a polishing process of some
sort.

I didn't know you can polish plastic fibres too. That's interesting.

I'll give it a try.

Flame polishing is a simple method applicable to many plastics. Flash it
through a hot flame (like a blue butane flame) and the surface melts and
is smothed by surface tension, solvent polishing works on some others.

sticking in a section of ball-point pen plastic (from behind/above the
ink) to activate the port in optical mode and serve as a crude coupler
to the tip of the TOSLink cable.
That's a nice hack. - Very interesting!

Is TOSlink LED or laser based?

The light out the back of my DVD player doesn't give the speckle
patterns I get with difuse light from a laser pointer, (and every
other laster I've seen up close) so I'd say it's an LED.

The vast majority of POF I have seen in the wild is 1000um (1mm) core.
1.8mm would get you more light, but with even greater degradation in
distance and data rates due to the larger core having even more modes
(leading to different optical path lengths and thus transit times, so
pulses get "fuzzy.")
In the mean time, I found a reference for 20 meter of 1 mm POF cable and
I'll start with that.

But it's a good idea to experiment with thicker POF later on. I
understand that the thicker core and the additional modes will "smear
out" the signal more.

Maybe an 0805 SMT LED could be a good match for a imm POF, possibly a
down-firing (bottom emitting) LED aligned with a 1.1mm hole in the PCB...
(custom PCB ballpark $5 from several sources)

--
ŘŞ