Materials World Network: Understanding the Optical Response of Designer Epsilon-Near-Zero Materials

The area of optical metamaterials - nanostructured composites with tailored optical properties - has experienced explosive growth over the past decade, fueled in part by rapid developments in fabrication, characterization, computational science and theory. Over the years, various metamaterials have been developed to enable several groundbreaking applications, such as superlens, electromagnetic cloaks, ideal optical couplers and optical black holes. In addition, they hold the promise to revolutionize beam steering, coupling of light between far- and near-field and many other photonics-related areas. Many of the unique aspects of light control realized in metamaterials originate from the possibility of achieving vanishingly small permittivity, materials which are often referred to as epsilon-near-zero (ENZ) metamaterials. Indeed, these materials form the inner layer of optical cloaks, enable efficient light transfer through subwavelength slits, and have been suggested as the foundation for metatronic circuitry. Therefore, the creation of ENZ materials and, more importantly, the understanding of their interaction with light inside complex optical structures, have become increasingly important for future multidisciplinary research for next-generation photonic materials. From the materials standpoint, ENZ response can be achieved either in vicinity of the plasma frequency in homogeneous systems whose optical response is dominated by free electrons or by combining distinct components with either positive or negative permittivity together in a single composite "meta-"material. Here we propose to perform a comprehensive study of light-matter interaction in complex ENZ material systems. The combined expertise of the international team will provide a unique opportunity to experimentally study the electromagnetic properties of complex ENZ-containing systems based upon both homogenous and composite materials, with ENZ frequencies spanning the visible to mid-IR frequency ranges and unified by common theoretical framework. Our joint unique experimental capabilities will allow us to delineate the universal physics associated with real ENZ materials and assess the practical benefits of these highly demanded media.

The results of the project could be critical for industries that make use of optical and photonic materials and devices. The processes and effects proposed to study in this project can form the basis of new devices with unprecedented functionalities for extreme sub-wavelength guiding, high-resolution imaging and bio- and chemical sensing, all-optical signal processing applications in future multiwavelength optical networks, optical interconnection of high-speed microprocessors or routers. All these application areas have strong presence UK industry and we will be working with the King's Business to identify the results meriting exploitation and IPR protection and will be targeting the potential users. In the first instance, photonic interconnects and integrated biosensing and gas sensing applications may be of immideate ineterest to industries, while in the long-term prospective, all-optical signal processing and imaging applications may become suitable for commercialisation.