The quest to develop faster and more powerful computers has led to one of the earliest, basic methods of counting being given at 21st-century makeover.
An international team of researchers, including Professor C. David Wright from the University of Exeter, have developed a nanoscale optical ‘abacus’ that uses light signals to perform arithmetic computations.
The innovative device works by counting pulses of light — in the same way that beads are used to count when using a conventional abacus — before storing the data.
The pioneering new technique could pave the way to new and more powerful computers that combine computing and storage functions in one element. This is a move away from conventional computers that treat these two functions as separate.
Professor C. David Wright, an expert in electronics engineering and co-author of the study, said: “This device is able to carry out all the basic functions you'd associate with the traditional abacus — addition, subtraction, multiplication and division — what's more it can do this using picosecond (one-thousandth of a billionth of a second) light pulses.”
Professor Wolfram Pernice from the Institute of Physics at Münster University is the lead author of the study. “In the article, we describe for the first time the realization of an abacus which operates in a purely optical way," Pernice said. "Rather than wooden beads as found on traditional abacuses, our innovative device calculates with pulses of light — and simultaneously stores the result."
The team’s optical abacus is so small it’s essentially invisible to the naked eye. It is installed on a photonic microchip that can be easily manufactured.
So far, the researchers have succeeded in calculating with two-digit numbers using two photonic phase-change cells, but the extension to large multi-digit numbers simply involves the use of more cells.
"Computing with light — and not with electrons, as is the case with traditional computers — means that we can develop much faster systems which can be connected using integrated optical waveguides," adds co-author Prof. Harish Bhaskaran from the University of Oxford.
The paper on this study was published in Nature Communications.