Optical fiber soon to see performance gains

Add black phosphorus to the growing list of super-materials. It promises to speed up data sent over optical fiber, amongst other things.

phosphorus lead image
University of Minnesota, College of Science and Engineering

We're seeing a surge in successful experiments with alternative, atom-thin materials that are going to speed up and reduce the size of computer chips. Black phosphorus is the latest super-material that promises efficiency in electronics. This one promises speed gains too.

Adding the substance, commonly found in match heads and tracer bullets, to optical circuits made out of silicon increases data speeds, according to a University of Minnesota research team, and reported by Dexter Johnson in the Institute of Electrical and Electronics Engineers' IEEE Spectrum publication.

Over fiber, the scientists claim they have obtained data transfer speeds of up to 3 billion bits per second—or about one high-definition movie in 30 seconds. For comparison, a two-hour HD movie can currently take around an hour to download over a commonly available residential 5 Mbits per second Internet connection.

Two-dimensional material

Black phosphorus is a two-dimensional material, like graphene, another few-atoms-thin material. Graphene is an ultra-thin, very strong, carbon-based miracle conductor. It's the best conductor ever found.

However, black phosphorus proffers a big difference to graphene in that it's got a band gap. Band gaps, caused by the structure of the atoms within the material, allow tuning and switching. That off-and-on is good in electronics. It's an important part of a semi-conductor. A band gap would allow for use in chips.

I recently wrote about another band gap-enabled, atoms-thin material called silicene in an article titled, "Materials breakthrough promises smaller chips." Silicene could be used in chips, but there are some drawbacks, including that the transistors disintegrate when exposed to air.


Where black phosphorus excels is that it can be used to detect light very efficiently. And as we know, light can be used to communicate.

So the idea is that if you create an optical circuit to allow on-chip processor cores to communicate with each other, and can keep the circuit small and efficient, as phosphorus promises to help do, you can create more, ever more powerful and smaller processor cores on a chip.

That means smaller and faster electronics overall.


This photo detecting on chips is an important element in the bet on future miniaturization of electronics. Another material called germanium has been heralded as a good way to photo-detect on chips, in other words do the same fast communications as black phosphorus. However, it's harder to make, or "grow," it on silicon optical circuits.

Black phosphorous can be grown separately and then transferred onto any material.

Real world

But it's the dual use that makes the substance particularly interesting. The computer chip may not be the only benefactor. High-speed data over fiber, sent optically, might be able to be recovered by black phosphorous photo-detectors. That's where the 3 billion bits per second HD movie experiment came from.

In any case, graphene, silicene, and black phosphorus will be battling it out soon for the title of best newcomer.

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