Researchers at the University of Oxford have developed a method using the polarization of light to maximize information storage density and computing performance using nanowires. Different wavelengths of light do not interact with each other – a charac­teristic used by fiberoptics to carry parallel streams of data. Similarly, different polarizations of light do not interact with each other either. Each polari­zation can be used as an independent information channel, enabling more information to be stored in multiple channels, hugely enhancing infor­mation density.

PhD student June Sang Lee from the 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.” In collaboration with C. David Wright, University of Exeter, the research team developed a HAD (hybridized-active-­dielectric) nanowire, using a hybrid glassy material which shows switchable material properties upon the illumination of optical pulses. Each nanowire shows selective responses to a specific polari­zation direction, so information can be simul­taneously processed using multiple polari­zations in different directions.

Using this concept, researchers have developed the first photonic computing processor to utilise polarisations of light. Photonic computing is carried out through multiple polari­zation channels, leading to an enhancement in computing density by several orders compared to that of conven­tional electronic chips. The computing speeds are faster because these nanowires are modulated by nanosecond optical pulses. 

For over a decade, researchers in Harish Bhaskaran’s lab in the Department of Materials, University of Oxford, have been looking into using light as a means to compute. Bhaskaran said: “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 polari­zation to dramatically paralle­lize infor­mation processing. Definitely early-stage work, 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!” (Source: Oxford U.)

Reference: J. S. Lee et al.: Polarization-selective reconfigurability in hybridized-active-dielectric nanowires, Sci. Adv. 8, abn9459 (2022); DOI: 10.1126/sciadv.abn9459

Link: Advanced Nanoscale Engineering, Dept. of Materials, University of Oxford, Oxford, UK