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..."

Comments

Deep inside the ISP boardrooms

[brogdon]

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.

Re:Speed of light?

[SkewlD00d]

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).

Learn some science?

[stevenj]

Was the subject line supposed to be ironic? Brewster's angle is a specific angle at which the reflections for one polarization are zero. (That is why you use polarized sunglasses...reflections off of water, ice, etcetera will tend to be mostly polarized perpendicular to the ground, so filtering that out cuts the glare.)

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.)