Oxford researchers create the world's first ultra-fast, polarisation-based photonic chip

The new chip is said to be 300 times faster and denser than present electronic chips

Researchers from the University of Oxford claim to have developed an ultrafast computing chip that maximises information storage density and processing performance by using distinct polarisations of light.

The results of the research have been published in Science Advances.

Wavelength and polarisation are two basic characteristics of light that may be used to encode and (de)multiplex information.

While there has been significant development in the field of wavelength-selective systems, polarisation-addressable active photonics has lagged far behind, owing to the lack of tunable and polarisation-selective nanostructures.

The fact that distinct wavelengths of light do not interact with each other is a quality that is exploited by fibre optics to transmit parallel streams of data.

In the same way, the various polarisations of light do not interact with one another. As a result, each polarisation may be employed as a separate information channel, allowing more data to be stored in several channels, greatly increasing information density.

Researchers working in Professor Harish Bhaskaran's lab at the Department of Materials at the University of Oxford have been investigating the possibility of utilising light as a means to compute for than a decade.

The Oxford research team, in collaboration with Professor C David Wright of the University of Exeter, produced a hybridised-active-dielectric (HAD) nanowire utilising a hybrid glassy material that demonstrates switchable material characteristics upon the illumination of optical pulses.

Because every nanowire demonstrates selective responses to a distinct polarisation direction, it is possible to concurrently process information utilising multiple polarisation directions.

Using this concept as a foundation, researchers have built the first photonic computer processor that makes use of different polarisations of light. The new chip is expected to be 300 times faster and denser than present electronic chips.

"This is just the beginning of what we would like to see in future, which is the exploitation of all degrees of freedoms that light offers, including polarisation to dramatically parallelise information processing," said Professor Bhaskaran, who led the research.

"Definitely early-stage work - our speed estimates still need research to verify them experimentally - but super exciting ideas that combine electronics, non-linear materials and computing. Lots of exciting prospects to work on which is always a great place to be in!"

First author and DPhil student June Sang Lee, Department of Materials, University of Oxford said: "We all know that the advantage of photonics over electronics is that light is faster and more functional over large bandwidths. So, our aim was to fully harness such advantages of photonics combining with tunable material to realise faster and denser information processing."

The details of the study come days after researchers at Canadian firm Xanadu said they had developed a quantum computer capable of doing a computation in a fraction of a second that would take a traditional computer 9,000 years to finish.

The researchers wrote in a paper that their quantum computer, named Borealis, accomplished a computing work based on Gaussian Boson sampling (GBS) in only 36 microseconds, while today's algorithms and supercomputers would take 9,000 years to complete the same operation.