The Microphotonics Revolution

MycoMan writes "Interesting article about photonic switching research, but there's a sentence in it that reads: 'So far, communications systems have managed to keep up because the volume of phone calls, Web pages and videostreams that optical fibers can carry is doubling every nine months, thanks in large part to the ability to squeeze more wavelengths of light into each fiber.' Doubling every nine months - is this really true?" True or not, it's an interesting article. Enjoy.

Comments

Re:Photonic Motherboards?

[softsign]

These guys aren't saying they're going to build a motherboard with fibre-optic cables. They're talking about a silicon fabrication process that is used to build waveguides (micro-fibre-optic cables, if you will) into the silicon wafer itself.

It's not the speed of light that matters here (the speed of an electrical signal is virtually identical to a light signal) - it's the switching speed. Even with the best CMOS processes out there today, there is still a finite switching time - the time it takes a transistor to go from one logic level to the other - that presents a barrier to the maximum available processing speed of the chip. With decreasing size and voltage you can improve the speed of the chip, but there's only so far you can go.

These people are exploring the likelihood that you may be able to build something analogous to a transistor that acts upon photons instead of electrons.

If they can succeed in making these feasible - then you have a technology that is potentially 1) faster than CMOS and 2) much more efficient.

That is huge. It's not just a frivolous new motherboard with lots of unwieldly wires built into it. It would be a one-piece integrated design that would in all likelihood run very cool and perhaps even faster than microelectronics ever will.

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Backbonebandwidth increasing even faster

[hrath]

Just a sidenote, UUNET's total backbone bandwidth has been increasing by 800-1000% every year since about 1994...

In San Jose at Broadbandyear John Sidgemore (Vice Chairman, MCI WorldCom & UUNET) said in a keynote:

"Bill Gates thinks that bandwidth should be free, of course we believe software should be free."

Heiko - who works for WCOM, but is not a mindless drone

Gilder's Law...

[cperciva]

states that bandwidth increases by a factor of three every year. This means doubling every 7-8 months.

This, compared with Moore's law, has interesting consequences; among them the fact that as time goes to infinity processing power is expensive, while bandwidth is cheap. This is reflected in the differences between IPv4 and IPv6: while IPv4 has data fields tightly packed together, IPv6 spaces them out in a manner designed for easy access by software. While IPv4 optimizes bandwidth, IPv6 optimizes computational power.

Will we ever hit a limit in bandwidth?

[dustpuppy]

Every year we keep creating better and better technologies which expand our available bandwidth for communications. Will we ever reach a point when the amount of data that we want to transmit saturates our communication bandwidth?

With 'everything' being networked and everything talking to everything else in the near future is it conceivable that our advances (such as the optical switching) won't keep up with the growth in transmitted data?

Could it reach the point where we have communication restrictions (like water restrictions :-). eg only allowed to send emails on odd days, or no emails over 3k in size :P

Re:Will we ever hit a limit in bandwidth?

[zaugg]

Well as well as fattening the pipes (and, hence, the "valves"), we can always lay down more of them.

If the world travels down a purely client/server model (read: dot net... well, not quite) the bandwitdth requirements grow _very_ quickly. Go down a distributed path, and local traffic stays local, and the network grows strong :)

Seems like the latter path is more sustainable, and more elegant.

zaugg

Re:Speed of Electrical Signal

[softsign]

If you can make a usable piece of hardware using only free space, sign up for the Nobel Prize, my friend. =)

In crown glass (I don't really want to figure out the velocity in silica fibre and can't seem to find it quickly), light travels at roughly 66% of its free-space velocity. This is, indeed, very close to 2 x 10^8 m/s.

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Hmm...

[babbage]

These guys say communications traffic is doubling every nine months.

Moore's law says that computing power doubles every eighteen months

The two seem to be moving at proportional rates. Interesting coincidence. Anyone wanna speculate about reasons for this? Just a glitch of the numbers, or does one have something to do with the other? How far back does this growth in communications speed go? Moore's law is claimed by some to go back in some way to the beginning of the Industrial Revolution, and with the telegraph and such I don't think it's impossible to speculate that communications has been doing the same thing.

So. Anyone care to put forth a hypothesis to explain this coincidence?