Metamaterials underpin transformation optics
Plasmonic materials that combine light confinement at the nanoscale with high-speed processing of signals have the potential to enable the next generation of information-processing devices. New plasmonics – other than metals – and optical materials with metal-like behaviour, have recently attracted a lot of attention due to the promise they hold. In the EU-funded project ATOMIC(opens in new window) (Advanced transformation optical materials for bio-imaging and light-concentration), researchers turned to compounds, including a new oxygen-depleted aluminium-doped zinc oxide (AZO). Synthesised for the first time, this transparent conductive oxide did not require the usual trade-off between magnitude and speed of externally changed optical properties. Experiments performed on thin AZO films showed a six-fold increase of the nonlinear Kerr refractive index at wavelengths located in the 1300 nm region. This translates into ultrafast light-induced refractive index changes of the order of unity, opening up new possibilities for their applications in optical signal processing as well as computing. Researchers looked into the class of nitrides. Titanium nitride was explored as an attractive alternative to conventional metals to fabricate low-loss plasmonic waveguides. Experiments carried out covered a broad wavelength range offering evidence of plasmonic interconnects reducing signal delays and proving their suitability as basic components for nanophotonic circuitry. ATOMIC outcomes are expected to pave the way towards future disruptive technologies such as heat-assisted magnetic recording that brings the promise of dramatically improving data storage. To date, 13 scientific publications have been widely received by the scientific community, as suggested by 250 citations acknowledging the project research.
