First-of-a-kind electro-optical device provides solution to faster and more energy efficient computing memories and processors

The team has created a first-of-a-kind electro-optical device that bridges the fields of optical and electronic computing. This provides an elegant solution to achieving faster and more energy efficient computer memories and processors.

Computing at the speed of light is an enticing prospect, and with this development it’s now within our grasp. While the use of light to perform various computing processes has previously been demonstrated, a compact device to interface with the electronic architecture of traditional computers has so far been lacking. The incompatibility of electrical and light-based computing stems from the fundamentally different interaction volumes for electrons and photons – the wavelength of light being much larger than that of electrons.

To overcome this fundamental problem, the Oxford- Münster-Exeter team came up with a solution to confine light into nanoscopic dimensions, as detailed in their paper Plasmonic nanogap enhanced phase change devices with dual electrical-optical functionality published in Science Advances, 29 November 2019. More specifically, they combined concepts from integrated photonics, plasmonics and electronic memory technologies to deliver a compact device that can operate simultaneously as an optical or electrical memory, and as a processor. Information can be stored and processed using either light or electrical signals, or indeed by any combination of the two.

 “This is a very promising path forward in computation, especially in fields where high processing efficiency is needed,” states Nikolaos Farmakidis, graduate student at Oxford and co-first author. Nathan Youngblood, the other co-first author, continues: “This naturally includes AI, where the needs for high-performance, low-power computing far exceeds our current capabilities. It is believed that interfacing light-based photonic computing with its electrical counterpart is the key to the next chapter in CMOS technologies.”

The work was carried out as part of the EU H2020 project Fun-COMP led by co-author Prof C David Wright from the University of Exeter, who added “Electronic and photonic computing each have their own advantages and disadvantages: it may be, by exploiting devices such as those we have developed in this work, that we can, ultimately, achieve the best of both worlds by working seamlessly in both domains”.