New Memory Chip which Stores Data with Light

A light-based memory chip that stores data permanently is a new development from University of Oxford and other scientists at the universities of Karlsruhe, Munster and Exeter. Taking materials already used in CDs and DVDs, the researchers say this chip is likely to significantly ramp up the speed of our modern computing.

As it is, computers now slow down to allow for electronic data to move between the processor and the memory. "There's no point using faster processors if the limiting factor is the shuttling of information to-and-from the memory -- the so-called von-Neumann bottleneck," said Professor Harish Bhaskaran, the research leader, in the release. "But we think using light can significantly speed this up."

Simply bridging the processor-memory gap with photons isn't efficient, though, because of the need to convert them back into electronic signals at each end. Instead, memory and processing capabilities would need be light-based too. Researchers have tried to create this kind of photonic memory before, but the results have always been volatile, requiring power in order to store data. For many applications -- such as computer disk drives -- it's essential to be able to store data indefinitely, with or without power.

Using light instead of electricity to move information between a computer’s memory and its processor could lead to much faster and more energy-efficient computers (see “Intel’s Laser Chips Could Make Data Centers Run Better”). But right now it is necessary to convert the optical signals to electrical ones and store the data electronically, which is relatively slow compared with the speed of today’s processors. The new “all-photonic” memory, which takes advantage of the same materials used in rewritable CDs and DVDs, is a step toward systems that achieve more efficient data transfer and storage, according to the technology’s inventors.

In the near term, a memory technology like this could be used to augment the performance of data centers and thus expand the kinds of applications possible thanks to cloud computing. Several major computing companies are developing systems for moving light around a chip using waveguides, or from one chip to another using optical cables like those common in the telecommunications industry. The technology is still far from commercialization. The researchers only demonstrated the ability to read and write several bits. More research and development will be needed to understand how exactly it can or should be applied.