MIT spin off company Ayar Labs is combining light and electronics to create faster, more efficient computers. The new optoelectronic chips are designed to speed up data transmission to and from conventional processor chips in a way that will also reduce energy consumption in chip-to-chip communications by 95 percent and could cut overall energy usages by large data firms by up to 50 percent.
Since the invention of the silicon chip 60 years ago, the power of computers has doubled every two years, but the speed at which computer systems work hasn't shown quite such dramatic progress. The problem is one of data transmission and the bottlenecks that any technology runs into, slowing down the whole to the speed of its most sluggish part.
Think of a computer as like an air passenger system. If you concentrate on the aircraft, airport runway architecture, supply logistics, and air traffic control, it's easy to speed up travel between, for example, New York and Washington DC to under one hour. That sounds fantastic, but if it takes you two hours to get through security at one hand and another two hours to collect your baggage at the other, then it's faster to drive.
It's the same with computers. Chips may be able to operate at lightning speed, but they still communicate with one another using copper wires that not only slow down the system, they also force the chips to waste energy sitting idle while the data is transferred. As long as the copper wires are there, so is the bottleneck.
One way of handling this problem is to create a computer that uses light instead of electricity. Such photonic chips take up little space, work literally at the speed of light, can send multiple signals at once on various wavelengths, and are very energy efficient – but their development, despite decades of research, is still far behind that of their electron-munching cousins.
The Ayar Labs solution to this conundrum is to create a hybrid chip that melds optical and electronic elements. This isn't new, but where previous attempts wasted energy by treating the photonic and electronic parts as separate elements, Ayar cut out the copper to create silicon chips that directly integrate optical components at a cost of pennies per chip.
Undertaken in collaboration with GlobalFoundries and building on the results of MIT's work for DARPA's Photonically Optimized Embedded Microprocessors (POEM) project, the creation of the hybrid chips saw engineers working on a new class of miniaturized optical components that include photodetectors, light modulators, waveguides, and optical filters. These can encode, transmit, and decode digital data sent over different wavelengths of light. They managed to incorporate these components into conventional chips by swapping out some electronic layers and replacing them with optical ones for a tightly configured design. Since the optical and electronics are on the same chip, there's no copper in the way and transmission is purely optical.
According to MIT, the first product of this new technology is an optical input-output system called Brilliant that is slated to hit the market in 2019. Meanwhile, Ayers Labs sees the new optoelectronic chips as having applications in supercomputer architecture as well as data centers and may even find its way into autonomous vehicles.
"We're starting out solving this bottleneck problem in traditional silicon chips, but ultimately we're excited about all the different places this technology will go," says Ayer Labs CEO says CEO Alex Wright-Gladstein. "This is going to change the availability of optics, and how the world can use optics, in ways beyond what we can predict right now."
Source: MIT
