Light-based or photonic computers have the potential to run at least twenty times faster than your laptop, not to mention the fact that they won't produce heat or suck up energy like existing devices. This is because they - in theory - would process data in the form of photons instead of electrons.
Light-based information that flies across internet cables is currently converted into slow electrons. But a better alternative would be to slow down the light and convert it into sound. And that's exactly what researchers from the University of Sydney in Australia achieved, 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. The information in the chip in acoustic form travels at a velocity five orders of magnitude slower than in the optical domain.
This means that computers could have the benefits of data delivered by light - high speeds, no heat caused by electronic resistance, and no interference from electromagnetic radiation - but would also be able to slow that data down enough so that computers chips could do something useful with it.
First, photonic information enters the chip as a pulse of light (yellow), where it interacts with a 'write' pulse (blue), producing an acoustic wave that stores the data. Another pulse of light, called the 'read' pulse (blue), then accesses this sound data and transmits as light once more (yellow). 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.
The fact that the team was able to convert the light into sound waves not only slowed it down, but also made data retrieval more accurate. The system worked across a broad bandwidth. Not being limited to a narrow bandwidth allows us to store and retrieve information at multiple wavelengths simultaneously, vastly increasing the efficiency of the device.
Image Credit: https://www.sciencealert.com/light-has-been-stored-as-sound-for-the-first-time