opticalcomputing
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Nano-scale mirror could be a breakthrough for optical computing
Using a mere 2,000 atoms of cesium, Professor Julien Laurat and his team at the Pierre and Marie Curie University in Paris have created the world's smallest mirror. According to postdoctoral fellow Neil Corzo, who is also lead author on the team's research paper published in the Physical Review Letters journal this week, the nano-mirror has the same level of reflectance as materials that require tens of millions of atoms and could one day lead to new advances in optical computing.
Entangled photons on a chip could lead to super-fast computers
Photon entanglement is one of the odder properties of quantum physics, but it promises a lot for computing -- if one photon can instantly affect another no matter how far away it is, you could make super-speedy computers and communications that aren't easily limited by physical distances. It hasn't been easy to get entanglement tech down to a manageable size, however, and that's where Italy's Università degli Studi di Pavia might just come to the rescue. Its researchers have developed a tiny emitter that could pump out entangled photons as part of an otherwise ordinary silicon chip. The device, which uses a ring shape to both rope in and emit light, measures just 20 microns across. That's hundreds of times smaller than existing devices, which are comparatively gigantic at a few millimeters wide.
Optical computing could benefit from new 'whispering gallery' fiber
It's a spooky feature of Grand Central Station that if you whisper something against the wall, your voice can resonate around the perimeter of the building and sneak up on you from behind. The same 'whispering gallery' principle is crucial to next-gen optical computing: light signals have to be sent on extremely circuitous journeys through 'microresonators', which temporarily bottle up the beams and thereby serve as memory. So far, microresonators have generally been made from silicon wafers etched with the a long series of loops. However, even the most precise etching leaves imperfections, which quickly cause the signal to lose its strength and fade away. Now, researchers at OFS Laboratories in Somerset, N. J., have come up with a different type of microresonator that could potentially hold onto light 100 times longer. The new technology diverts light onto a stretch of optic fiber that has been specially manufactured with tiny step-changes in its diameter. When the signal hits this abrupt change, it reverses and goes back the opposite way -- and, if it hits another diameter change, it will effectively enter a whispering gallery inside the fiber, bouncing up and down with only minor attenuation. The OFS scientists claim their microresonator could appear in "specialized devices" in just two or three years, which is good to hear, because electronics is starting to get old.
Optical 'diode' lends hope to photonic computing, rayguns
The trouble with pesky Photon, at least as far as ultra-fast optical computing is concerned, is that he keeps coming back. If a data-carrying beam of light collides with reflections bouncing around between the components of a chip, it can suffer enough interference to make people yearn for the good old days of electrons. What's needed is the optical equivalent of a diode, which only allows light to pass one way, and that's exactly what researchers at Caltech and the University of California claim to have developed. As you'll see in the photo after the break, their metallic-silicon optical waveguide allows light to travel smoothly from left to right, but it breaks up and dissipates any photons traveling in the opposite direction. This is all good, because there's no point having futuristic 50Gbps optical interconnects if our CPUs lag behind. Light up the source link for a fuller explanation.
Fujitsu's quantum dot laser fires data at 25Gbps, not just for show
Fujitsu just announced what's reportedly the world's first quantum dot laser capable of 25 gigabits per second of data transmission. Go on -- there's no need to hold your applause. Now, we've seen lasers beam packets at 1.2 terabits per second over miles of open ground, and up to 15.5Tbps through a fat optical pipe, so why would a measly 25Gbps attract our attention? Only because we hear that the IEEE is hoping to create a 100Gbps ethernet standard by 2010 (that's now!) and four of Fujitsu's new nanocrystal lasers bundled together just so happen to fulfill that requirement. It also doesn't hurt that the company's quantum dot solution reportedly uses less electricity than the competition, and that Fujitsu has a spin-off firm -- QD Laser -- champing at the bit to commercialize the technology. All in all, this tech seems like it might actually take off... assuming early adopters are more successful than major corporations at deploying the requisite fiber. Either that, or we'll just enjoy some seriously speedy displays and external drives, both of which sound downright delightful in their own right.
Chinese scientists demonstrate 2Mbps internet connection over LED
LED data transmission used to be all the rage -- we fondly remember beaming Palm Pilot contacts via IrDA. Then we got omni-directional Bluetooth and building-penetrating WiFi, and put all that caveman stuff behind us. But now, scientists the world over are looking to bring back line-of-sight networking, and the latest demonstration has Chinese researchers streaming video to a laptop with naught but ceiling-mounted blue LEDs. The Chinese Academy of Sciences claims to have realized a 2Mbit per second internet connection that transmits data simply by modulating the flicker of the little diodes, and imperceptibly enough to have them serve as room lighting as well. Like Boston University before them, the Chinese scholars see short-range LED networks controlling smart appliances. It's not quite the gigabit speed you'd get from laser diodes, but this way you'll get more mileage out of those expensive new bulbs, eh?
Germanium lasers offer ray of hope for optical computing
Bandwidth scarcity, is there any more pressing global issue that we're faced with today? We think not. Given the exponential growth in both computing power and software's exploitation and expectation of greater resources, it's no surprise that at some point we'll have to look beyond simple electrical currents as the transporters of our data. One bold step taken in that direction has been the demonstration of an operational germanium-on-silicon laser by researchers at MIT. By tweaking the electron count in germanium atoms with the help of some added phosphorous, they've been able to coax them into a photon-emitting state of being -- something nobody thought possible with indirect bandgap semiconductors. Perhaps the best part of this is that germanium can be integrated relatively easily into current manufacturing processes, meaning that light-based internal communication within our computers is now at least a tiny bit closer to becoming a reality.
Diminutive cable holds promise in medical, solar realms
We tend to prefer our electronics to be as far from invasive as possible, and that definitely includes cabling. While we'd take wireless over the corded approach any day, tethered applications still have their place, and a diminutive new cable is showing bigtime promise in a few prominent fields. A research team has developed a cable that resembles that of an old fashioned coaxial strand, yet it's reportedly "much thinner than a human hair" and can transmit visible light. By constructing a cable about 300-nanometers wide which houses an inner wire of carbon surrounded by an insulator and an outer wire of aluminum, visible light can pass through, paving the way for its use in highly efficient solar energy cells, or furthermore, "miniature electrical circuitry and microscopic light-based switching devices for optical computing." Researchers even suggest that it could be used in retinal implants or "detecting single molecules of pathogens in the body." We're not yet sure just how potent or powerful these itty bitty cables can be, but judging by size alone, we're halfway sold already.
