When it comes to silicon-based computer chips, we're fast approaching the limit of how small we can effectively shrink the die, with companies, such as IBM, creating 5nm transistors which are expected to hit the mainstream by 2020. So researchers have worked tirelessly to find suitable alternatives to this problem, from organic-based materials to quantum computing. However, these haven't proven useful yet, with the latter requiring massive amounts of energy to cool the system to near absolute zero for it to function properly.
Light-based computing has been explored in the past, to varying success. If you currently utilize a fiber internet connection in your home or office, you're already using light to send-and-receive data. So experts in this field aimed to build a computer chip that would allow future chips to have improved processing capabilities . The great thing about light, in this case, is that it will not slow down - unless specifically required to - due to heat or other factors marring current silicon-based technology.
Although only in the theoretical-phase right now, researchers at the University of Sydney in Australia effectively showcased how they could get around the properties of light - called photons - by converting it to 'phonons', a wave similar to that of sound. How this is achieved, is by sending a package of 'data photons' through a waveguide that slows them down, and having them interact with a 'write' pulse. This increases the wavelength of the photons by the desired frequency which turns it into a 'phonon'.
By doing this, the research showed that once the photons were effectively converted into a phonon, they were able to store information in the form of a wave, inside the specialized chip. This could then be retrieved by sending a 'read' pulse which then interacts with the phonon, to obtain the information and decode it using specific metrics.
Even though the phonon only remained within the waveguide for a mere 10 nanoseconds, the paper noted that the team behind the project managed to break the gigahertz barrier with this technology, which up to now only reached below a megahertz. Also, the aforementioned project only managed to store information at present and did not function as a processor yet, but more like memory.
Although this is most likely years away from becoming a mainstream technology, it shows how the simple properties of light can be molded to possibly overcome the fundamental barriers we face in the computing space at the moment.