Nanomaterials for photonics
Rapid advances in the field of nanomaterials with exotic optical, electrical and magnetic properties are providing important building blocks for a field of growing importance. The EU-funded training network PHANTASY (Photonic applications of nanoparticle assemblies and systems) brought together three European partners and one each from Japan and Russia to develop advanced nanostructures for the manipulation of light. Scientists and fellows focused on colloidal assemblies, nanoparticles, oxides and metals. Photonic crystals are periodic structures that can control the flow of light in interesting ways. Given their multiple reflective surfaces on very small length scales similar to the wavelength of incident light, they can force light around sharp turns or even trap it completely. The team produced self-assembled colloidal photonic crystals and plasmonic crystals as well as heterocrystals made from silica and polystyrene on both rigid and flexible substrates. Researchers then filled in the gaps amongst crystals with metals, polymers or oxides using atomic layer deposition, and characterised the properties of the novel nanoparticle systems. The newly developed materials demonstrated their ability to change their properties (e.g. their colour) by external stimuli, such as stress or electric field. This renders them useful for applications ranging from optical circuits in communications to energy harvesting and energy storage. Another part of work was geared towards developing a metallodielectric colloidal crystal platform for plasmonic circuits, optical transformations and quantum information processing. Scientists prepared plasmonic-photonic hybrid crystals and arrays of metal and semiconductor nanowires using channels of asbestos as templates. The team also synthesised metal-coated photonic structures and thoroughly investigated a variety of surface modes. Results showed that deep corrugations in optically transparent metal films enable resonance overlapping that can facilitate photonic integration and reduce fabrication costs.
Keywords
Nanomaterials, photonics, PHANTASY, nanoparticle assemblies, nanostructures
