Although such supercomputers are still experimental, they could potentially deliver computing speeds ten times faster than present day computers while drastically diminishing power usage.
The fact that the switch functions at a range of temperatures, offers fast data transfer and requires less power could also make it useful for transferring data from instruments employed in space, where power is constrained and temperatures vary extensively. “Making electronic connections to systems operating at extremely cold temperatures is highly challenging, but optics can provide a solution,” says head author Michael Gehl, Sandia National Laboratories in New Mexico. “Our small switch enables data to be transferred out of the cold region using light moving through an optical fibre rather than electricity.”
In the journal of Optical Society for high impact studies, Optica Gehl and his team members illustrate their novel silicon micro-disk modulator and reveal that it can transfer data in regions as cold as 4.8 Kelvin. The equipment was structured with standard methods used to prepare CMOS computer chips that imply it can be conveniently integrated onto chips comprising electrical components.
“It is one of the primary examples of an active silicon optical device functioning at such a low temperature,” says Gehl. “Our equipment could potentially revolutionize technologies that are constrained by how rapid you can transfer information in and out of a cold environment electrically.”
The micro-disk modulator needs very less power to function around 1000 times less power than present day’s commercially available electro-optical switches that could also aids reducing the heat the device contributes to the cold environment.
For preparing the novel device, the scientists structured a small silicon waveguide next to a silicon micro-disk only 3.5 microns in diameter. Light coming through the waveguide move into the micro-disk and travel around the disk and not move straight through the waveguide. Adding impurities to the silicon micro-disk prepares an electronic junction to which a voltage can be placed. The voltage alters the substance’s properties in a way that combats the light from moving into the disk and enables it to instead pass through the waveguide.
To research the micro-disk modulator, the scientists placed it inside a cryostat, a small vacuum chamber that can cool what is inside it to very low temperatures. The micro-disk modulator transformed an electronic signal sent into the cryostat to an optical signal. The scientists then analysed the optical signal coming out of the cryostat to estimate how well it matched the incoming electronic data.
This work develops on years of effort to introduce silicon photonic devices for optical communication and high performance computing applications, headed by the Applied Photonics Microsystems group at Sandia. Further, the researchers wish to illustrate that their device functions with data generated inside the low – temperature environment.