Using an optimized laser nanofabrication technique, researchers have engineered one of the smallest nanowires made from the optical material chalcogenide glass. The nanowires could lead to the creation of a photonic chip — considered by many to be the holy grail of optics. The investigators, from Swinburne University of Technology and the Australian National University (ANU), have fabricated nanowires with a diameter of 68 nm — about 1000 times thinner than a human hair — out of the chalcogenide glass, something never done before at this scale. They believe that this represents an enormous step toward faster and more efficient Internet connectivity using photonic chips, which use light exclusively to pass data between computers. Fiber optic cables transport information using photons over long distances. The photons are converted into an electronic signal, which modern routers must sort before sending off to the correct recipients. This need for conversion means that there is a speed limit hindering the current system. Australian researchers have engineered optical nanowires with a diameter of 68 nm, about 1000 times thinner than a human hair. It’s an important step toward developing photonic chips, which could enable a faster and more sustainable Internet. (Image: Center for Micro-Photonics of the Swinburne University of Technology / CUDOS) Creating a router that could sort the packets of light without the need to convert the signal would not only result in a much faster Internet, but a more sustainable one, reducing the electricity required to run network equipment. But the scientists aren’t there yet. The chip realization will rely on a range of factors, including the fabrication of nanomaterials and the researchers’ ability to harness a unique optical property known as the “nonlinear effect.” Until now, researchers have been able to make nanowires of this size only in polymers, which don’t have the same unique characteristics as chalcogenide glass. Chalcogenide exhibits the nonlinear effect, which means its optical density changes according to the applied light intensity. “If you pump high-density light into an optic fiber made of nonlinear material, you can actually change its properties, and therefore change the way other light moves along it,” said Swinburne University’s Elisa Nicoletti, lead author of the study. It is this combination of tiny materials and nonlinearity that has brought the researchers one step closer to their ultimate goal. “Not many people realize this, but the Internet is a major energy consumer. It’s projected that, in the next decade it will count for half of the world’s energy use,” said Min Gu, director of the Swinburne arm of the Center for Ultrahigh Bandwidth Devices for Optical Systems, an ARC Center of Excellence. “So making it more efficient will make a huge difference to our carbon footprint.” The publication of the team’s findings comes just weeks after Swinburne and ANU were named in a list of the world’s top 100 universities in the field of physics research by the Academic Ranking of World Universities. The research was published in Nano Letters. For more information, visit: www.swinburne.edu or www.anu.edu