Fiber Optics In Harsh Environments

[TimWilborne 108]

Currently we still use copper lines for Ethernet. If one of the copper cables gets cut (and they do, lots of overhead movement) we can splice the cable together till we can replace the whole cable or a section of it. I know they make splices for fiber optics. I guess my question is in a very harsh environment, it a fiber optic cable gets cut, will the contaminants in the air get in the cable before it is repaired and affect the communications performance?

[Ken Moore 23]

We only use fiber for long runs (i.e. between buildings), and it is run inside of riged conduit. At the time we ran our fiber it was verrrry expensive, and we didn't want to take any chances. But just guessing, I think that it would depend on the specific environment. Before making the splice, the ends are cut again to ensure you have a nice, square cut, then cleaned, then bonded together. So, even if your environment contaminated the cut end, you would be removing this, before splicing. So the question is would your environment contaminate the fresh cut in the few seconds it's exposed, after the fresh cut and before it's bonded back together?

[TimWilborne 108]

Lots of steel dust. You can see it in the air when in the ceiling where it would be ran. May be I should ask a simpler question since it don't know a thing about fiber optics. Can the dust travel into the fiber optic wire or will it just settle on the end (are fiber optic cables microscopical hollow)? We don't have a problem with the copper but the limit is 328 ft and we have one run well over 400 ft. Even this one operates fine but it not the proper way to do it.

[waynes 8]

Hi, It is possible for the dust to get onto the end of the cable and block it, yes. Simply use clean alcohol to clean of the end. Usually the fibre guys simply cut the cables and resplice them, so the dust wont usually be an issue.

[TimWilborne 108]

So does that mean fiber cables are not hollow?

[waynes 8]

NO!!! Fibre is simply an extended glass tube which allows light to travel through it. The glass is a medium as copper would be. It is a very intersting medium to use. You can also get different types of fibre optic. The one I use has a wavelength of 850nm (multi mode fibre). This is good for up to 2km. There is another type of fibre which uses a wavelength of 1300nm and this is good for running comms over greater distances. This fibre is much more expensive and so are the converters. One which will suite you more is the plastic fibre. There are some new advancements in this field and you literally cut this fibre with a knife, hold it next to each other and the comms will continue. Remember that the distance it can carry comms is far less than multimode fibre. Hope this helps.

[TimWilborne 108]

Thanks for the info

[Money4Nothing 0]

Fiber Optics cables are not hollow, but it does act like a "hollow" media. Around the glass fiber itself is a cladding which provides reflective properties to the overall structure. The fiber is the transmission media, but the cladding is the outer barrier to the optical signal. The cladding is just as important as the fiber. Without it the light will escape the fiber and the signal will attenuate. When you make a splice, you must have undamaged cladding around all your fiber, and the end of the fiber must be cleaved and cleaned properly. $