Laser fiber-optics connection project
Driz wrote 10/24/2019 at 08:32 • 0 pointsHi there
Does anyone have an idea for a good and stable light source (Laser would be best) either in 850 or 1550 nm, which is inexpensive and most important can be easily connected to the fiber optic cable? A standard connection via a SC or LC connector would be perfect.
Am open to literallly all suggestion :)
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Hi guys I ordered an SFP-Port online:
Intellinet 507486 SFP-Transceiver-Module 1.000 MBit/s 10 km Modultype LX
I tore it down to see how I can maybe connect to the Laser driver circuit as Koen van Vliet suggested. The chips I found inside are on the front side:
- HE24C64: didn't find anything about that, but it looks like a ROM Chip
- TR3 K (the K is probably the date code): it looks exactly like the power mosfet NTR4503N from ON Semiconductors
and on the backside a
MYSON CENTURY CS6721 (2.5GBPS Post Amplifier and 1.25GBPS LD Driver with MCU).
I am honestly completly lost on how I can control the Laser emitting part with an Arduino. I have never worked with such a complicated circuit board.
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i added pictures from the front and backside of the circuit board to the project side:
https://hackaday.io/project/168546/gallery#f58fe892fda78449a58273a08abdb05f
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Have a look at the system block diagram in the CS6721 datasheet. It shows you how the laser is connected to a current source.
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Your LC cable should fit the recepticle of the SFP module, so I am not sure what you mean.
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You can get used 850nm GBIC/SFP+ modules cheap on Ebay, e.g. https://www.ebay.de/itm/BROCADE-Brocade-Transceiver-8Gbit-SW-SFP-57-1000012-01-M57-1000012-01-/382453352664
Not sure what you have in mind, but it would seem to fit your description.
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that's a great idea. Any idea how i can just use the laser but still saving the line up of the laser with the opening? The coupling of the laser with the fiber is the trickiest part.
here is a tear down video of an SFP so you know what I mean: https://www.youtube.com/watch?v=lt-q43kIVJM
i want to control the laser with an arduino..
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If you leave the SFP mostly intact there should not be any alignment issues. Just plug in an LC-terminated fiber and you're good to go.
The SFP module contains some smart electronics for controlling the laser transmitter and receiver. It seems like you are only interested in directly turning the laser light on and off using the Arduino. You can try to use the existing laser driver circuit on the SFP module or create one from scratch. These lasers are typically driven by a constant current source. You can use the Arduino to turn the current to the laser diode on and off. You will of course need to bypass the SFP module electronics.
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What about just buying old $1 SFP modules?
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that's a great idea. do you have any idea how I can just use the laser from it? I explained it further in the thread above
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Hi!
I recently came across so-called VCSEL (vertical cavity surface emitting lasers) that could fit you nicely. They come in a standard 3mm LED package, and send out a strong, focused beam of IR light (somewhere in the 850nm range).
4° of beam divergence and I think up to 300mw/sr at only 10mA of current. They only cost 4€ on DigiKey too, and you can get them in different casing styles and with larger beam divergence, if you need it.
Not sure how to connect them to fiber optic cables, but you can always use a 3D printer for some small adapters.
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