For the first time ever, scientists have stored light-based information as sound waves on a computer chip – something the researchers compare to capturing lightning as thunder.
Finding a way for a computer chip to be able to retrieve and process information stored in photons is tough for the one thing that makes light so appealing: it’s too damn fast for existing microchips to read. This is why light-based information that flies across internet cables is currently converted into slow electrons.
A better alternative would be to slow down the light and convert it into sound.
The team did this by developing a memory system that accurately transfers between light and sound waves on a photonic microchip – the kind of chip that will be used in light-based computers.
First, photonic information enters the chip as a pulse of light, where it interacts with a ‘write’ pulse, producing an acoustic wave that stores the data. Another pulse of light, called the ‘read’ pulse, then accesses this sound data and transmits as light once more.
While unimpeded light will pass through the chip in 2 to 3 nanoseconds, once stored as a sound wave, information can remain on the chip for up to 10 nanoseconds, long enough for it to be retrieved and processed.