Researchers Make Important Step to Photonic Microchips

Written by John Ponio    Wednesday, 23 November 2011 17:37

Fiber Optic Cable End

In our world today, just about every computer uses electricity to process its information. The transistor inside of a CPU is either on or off, depending on the flow of electrons. Something you may not have known scientists were working on is a microchip that doesn't use electrons, but uses light. Light is already commonly used for data transmission; but after the light travels through the fiber-optic cable, the signal must be turned into electrons so the computer can understand it. From being faster than electrons to the gigantic spectrum of light than can be used for higher bandwidth inside of cables, light has all sorts of advantages to electrons. A problem that scientists have been running into with photonic microchips, though, is making sure that light can't be reflected back into the lasers to cause interference. A form of garnet allows such one-way travel of light, but previously researches have had trouble getting the garnet to stick to silicon. That's what this new story is about: Caroline Ross, the Professor of Materials Science and Engineering at MIT, has found a way. The article say:

The researchers were able to deposit a thin film of garnet to cover one half of a loop connected to a light-transmitting channel on the chip. The result was that light traveling through the chip in one direction passes freely, while a beam going the other way gets diverted into the loop.

The even better part? This can all be done with current microchip manufacturing processes, meaning that it won't be hard for the industry to change over. You can read the paper about it (for more than a summary you have to pay, sadly) here, and read a little more in-depth article about it here.