Shining Light On (And Through) MEMS

An unnamed correspondent pointed out this story at Red Herring about the small-but-not-nanotech devices known as MEMS (microelectromechanical systems). The article focuses on the use that these devices can have in the form of switches enabling optical routing. At present, despite the huge carrying capacity of fiber optics, routing their signals is slower to accomplish and less developed in general than that for data sent as electrical signals. (But on what planet are devices 1-10 millimeters in size "smaller than the width of a human hair"?)

Comments

Re:Why the 'human hair'?

[squiggleslash]

Well, 1 human hair is exactly one US billionth of the volume of a small car. The actual scale is:

• 1,000,000,000,000 human hairs = small car
• 10 small cars = small truck
• 100 trucks = football pitch
• 1000 football pitches = New York City
• 100,000 New York Cities = Texas

It's pretty obvious when you think about it...

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Pure optical switching

[Anonymous Coward]

I took digital circuit design (EE194) in my first year of my EE degree. In that class, we were tought (among other things) that any digital logic circuit could be built using NAND gates.

I'll explain - The primitives most of us are familiar with are AND, OR, and NOT. A NAND gate is an AND gate with its output wired to a NOT gate. Two 1 (on) inputs and you get a 0 output. Any other combination results in a 1 output. Using this gate, we can use the following scenarios:

• NOT - The single input wired to both inputs of a NAND gate.
• AND - Two inputs to a NAND, then that output wired to our NOT from above.
• OR - Each input wired to our NOT and each output of the NOT gates to a NAND gate.

From these primitives (all from a NAND gate) we can build virtually every logic curcuit needed.

How does this pertain to the story? Optical switching is limited by the inability to look at an IP packet and determine its destination interface because the light cannot be processed (currently) without converting it to electricity, running that through a CPU, and then re-converting it back to optical light. Before optical switches/routers/computers/etc. become redily available at a cheap price (a few percent more than today's equipment), we must have a complete computer foundation based on an optical NAND gate. Of course the technology could be enhanced in the future, but that level could be reached in a short period of time. Does anyone know if such a beast exists today? If not, it would probably drive costs down quickly. If they do exist, why are they not in use today?

JMTC (Just my two cents)

SciAm's current issue.

[interiot]

Scientific American's current issue contains several articles on optical networks and prospects for switching and routing them without electronics.
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fiber optic slowness

[jpostel]

The slowness of fiber optic switching is due to the fact that it is currently done by converting the signal to electrical, switching it, then converting back to optical. There are many technologies currently in development to take care of many of the problems with optical switching. The problem with them is that they have been in development for a while now. I was working on opto-electronic modulator research at Bell Labs in 1996 and the technology is still not widely used. Like most really cool technology, it will be a while before we see any of this in wide spread use.