Plasmonics on silicon promising for light-based computing
Their research published in Nature Communications under the title “Modular nonlinear hybrid plasmonic circuit”describes a device formed by two in-series plasmonic elements on a SOI waveguide: a mode converter and a focuser. The focuser combines a taper with a sharp tip of nanometre scale, which functions as a nonlinear nanoscale light source. The hybrid plasmonic integrated circuit (HPIC) offers a bridge between industry-standard silicon photonic systems and the metal-based waveguides that can be made 100 times smaller while retaining efficiency, explains lead author Dr Alessandro Tuniz from the University of Sydney Nano Institute and School of Physics. The researchers have shown that they can achieve data manipulation at 100 times smaller than the wavelength of light carrying the information.
“This sort of efficiency and miniaturisation will be essential in transforming computer processing to be based on light. It will also be very useful in the development of quantum-optical information systems, a promising platform for future quantum computers,” said Associate Professor Stefano Palomba, a co-author from the University of Sydney and Nanophotonics Leader at Sydney Nano.
“Eventually we expect photonic information will migrate to the CPU, the heart of any modern computer.”
On-chip nanometre-scale devices that use metals (known as “plasmonic” devices) allow for functionality that no conventional photonic device allows. Most notably, they efficiently compress light down to a few billionths of a metre and thus achieve hugely enhanced, interference-free, light-to-matter interactions.
“We have shown that two separate designs can be joined together to enhance a run-of-the-mill chip that previously did nothing special,” Dr Tuniz said. This modular approach allows for rapid rotation of light polarisation in the chip and, because of that rotation, quickly permits nano-focusing down to about 100 times less than the wavelength.
University of Sydney – www.sydney.edu.au