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Plastic Optical Fibre: Cheap and Bendy
Motivator_Bob writes: "The Sydney Morning Herald has an article on making optical fibres from plastic rather than the traditional glass."Advances in optical-fibre making at the Australian Photonics research centre could bring communications at the speed of light into Australian homes and businesses in the next few years. The advance - microstructured polymer optical fibres (MPOF) - allows the manufacture of optical fibres that are much smaller, cheaper, more rugged and easier to make than glass fibres..."
Interesting quote:
Maybe I'm just naive (probably), but the limiting factor today for broadband Internet access is the cost of the bandwidth, possibly due to the stranglehold a few key companies have on access to their backbones. The cable that comes into my house can be used for speeds in excess of 30Mbps, if I recall correctly, yet I have a mere 1.5-2Mbps (at $39.95/mo). Admittedly, DSL has technical limitations on speed, but even so, the large limiting factor seems to be the cost of an OC-12/48/96 connection to the 'Net, right?
When is that gonna change?!? What is needed to bring about that change? Regulation?
No, all the dark fibre we have in the states may be lit up in the future because a cheaper new way of bridging the last mile has just been invented. There's no reason to replace already-installed fibre, it's not "obsolete".
main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
Exec 1: Gee guys, with this cheaper fiber, we could roll out much better speeds than what we get on the copper we use now!
Execs #2 & #3: Woo-hoo, that'll really help us get a leg up on the competition!
Exec #1: Oh, wait... We don't have any competition. We don't have to share our lines with anyone, so no one else can get their foot in the door here. I guess we'll have to bonus our expansion money out to ourselves, instead.
Exec #2 (holding plastic fiber up to his eye) : Hey, Dick, I think I can see you through this thing. Neato. Somebody get me a martini.
This tagline is umop apisdn.
Single-mode fiber has a mixture of materials that have varying indices of reflection, so that the cable is a light guide instead of a light tunnel. This allows for a shorter path because the light is kept closer to the middle. Btw, the latency of copper is much, much greater than typical single or multimode fiber because of capacitive and inductive coupling. Fiber mainly has the advantage of higher bandwidth and noise immunity, but it wont ever reduce you ping beyond (distance / c).
The biggest trick the devil pulled was letting lawyers become politicians so they can write the laws.
Unlike photons, electrons have mass. Nothing with mass moves at anything close to the speed of light.
What is the speed of electrons down a copper wire?
I'll admit that I didn't do the math to re-check this, but I seem to remember the velocity of electrons in copper wire being on the order of a few cm/second - much less than the speed of light. The confusion my be coming from the fact that when you stick an extra electron in the end of an otherwise neutrally charged wire, the spare charge sets up an electrical field that pushes a different electron out the other end (assuming it's grounded or generally has another place to go to). It's the electrical field that travels at the speed of light, not the electrons themselves.
>In fact, as light in fibre optic cabling bounces off the insides of the plastic tubing, it takes a less direct route and thus technically has a _higher_ latency than copper wire.
Ummm.. not quite. It's true that the light bounces around inside the fiber, but due to the low index difference between the core of the fiber and it's surrounding cladding the angle of the bounce is pretty small and wouldn't really increase the distance the light needs to travel The distance increase is proportional to 1/cos[angle] so when the angle is near zero, cos[angle] is near 1 and 1/cos[angle] is pretty near 1 meaning no big change in the distance traveled by Joe Photon. For electrical wires, speed is limited by the capacitance/inductance ratio of the cable and is typically around 2-3 times slower than free-space light.
All in all, it's a good thing that electrons don't go the speed of light in our house wiring - I used to work with a synchrotron, which is a device that gets the electrons moving at relativistic speeds, and whenever the beam of elecrons went around a corner it produced enough X-rays due to the angular acceleration to flash-fry a horse. Be glad that copper wire electrons are slow, since if they were fast we'd get cooked every time a bit of house wiring was anything less than perfectly straight.
I just read that telecoms have an excess of long haul bandwidth, which means that the issues are the cost of the last mile and consumer uptake.
I wouldn't be surprised if the main issue is the latter. I have spent some time trying to convince one of my coworkers at a major computer hardware company to get broadband, but he doesn't think he needs it. The uses of broadband are not necessarily obvious if you don't have it.
I also read that several telecoms will try to address this issues by selling capped broadband at a lower price.
The relevant quantity in fibers is the critical angle, beyond which all light is reflected inside the higher-index core. (Actually, the whole ray-optics picture is not completely accurate for fibers with features, like the core size, comparable to the wavelength...but it's qualitatively the right idea.) (Which, by the way, has nothing to do with the reflection disappearing from the puddle, since that is a reflection into the lower-index medium, air. The puddle effect has more to do with your shadow blocking the light.)
Note also, by the way, that it's not so much that the index of the polymer fiber core has been increased, its that the effective index of the cladding is decreased (by adding lots of thin holes/veins, hence the name microstructured fiber). And you can do the same thing with glass fibers. (Because of the higher effective contrast, you can confine light more tightly and e.g. enhance nonlinear effects.
(You were on the right track that it's the bending light loss, and the advantage therein of higher index contrast, that the article was referring to.)
Microstructuring can also go in the other direction to photonic crystal fibers and guiding light in air.)
If a thing is not diminished by being shared, it is not rightly owned if it is only owned & not shared. S. Augustine