Fiberized Platforms for Integrated Nanosheet Materials

Materials that can be produced in very thin films, a few nanometres thick, are currently at the forefront of an exciting wave of scientific research. Compared to their traditional bulk material counterparts, these "nanosheet materials" present many unique optical and electronic properties that are advantageous for use in wide-ranging areas such as communications, imaging, sensing, and energy harvesting, to name but a few. Moreover, the properties of the nanosheet materials can be readily tuned by changing the layer thickness, stacking different materials together, and through electronic control, further expanding their application potential. However, there is a significant challenge to working with these atomically thin films: when optical signals are focused directly through the material the light-matter overlap is weak, so that most of the light passes through unperturbed. This makes the construction of efficient photonic devices that draw on the properties of the nanosheet materials very difficult.

The work in this programme aims to address this issue by integrating the nanosheet materials directly within optical fibre platforms, which are famed for their exceptional light-guiding capabilities. The materials will be incorporated into the fibres through a specially designed "interaction window" that has been opened into the fibre's cladding. This configuration allows for light signals that are guided within the fibre to interact with the ultra-thin material over extended propagation lengths, without any disruption to their optical path. The components built into this platform will therefore be immediately compatible with existing fibre systems and networks, which will facilitate their wide-spread use in academia and industry alike. By choosing the right material and device design for the target wavelength regime, it will be possible to develop an array of highly functional optical and optoelectronic devices that are suitable for wide-ranging applications, including high-volume manufacturing, telecommunications, and quantum information. Furthermore, by introducing electrical contacts to control the material properties, these devices could also be tunable in their performance metrics and wavelength of operation, paving a way for the development of next generation "smart" - real-time adjustable - photonic systems. These all-fibre integrated nanosheet devices will be designed and optimized for efficiency, stability and durability; key requirements that will expedite their transition into the commercial domain.

This proposal aims to develop a platform technology that combines two of the most exciting technological breakthroughs of recent times - glass optical fibres and nanosheet materials - to develop a new generation of robust, compact, efficient and tunable photonic devices. Thus the success of this project will be measured by the uptake of these devices in wide-ranging areas including, but not limited to, high power laser development, optical communications, and quantum information systems. As a result, the outcomes will align with several key research areas including Photonic Materials, Optical Devices & Subsystems, Optical and Optoelectronic Devices, Optical Communications, and Quantum Optics, which fall under the themes 'ICT', 'Manufacturing the Future', and 'Quantum Technologies'.

Photonic Materials: A key goal of the project is to use the fibre platforms as a characterization test bed to advance the UK's knowledge of the rich and varied optoelectronic properties of the nanosheet materials. This knowledge base will not only be important for the academic community, as demonstrated via our partnerships with the Micronova Research Centre for Nanotechnology at Aalto University, but also for manufacturers and commercial end users of nanosheet materials, as they seek to determine the best materials and/or composites for their target applications.

Manufacturing: The UK has a strong laser manufacturing industry and the importance of laser-based manufacturing has been recognised by EPSRC through the support of initiatives such as the Centre for Innovative Manufacturing in Laser-Based Production Processes (http://www.cim-laser.ac.uk/). Components developed within this project such as broadband polarizers, saturable absorbers, tunable filters, mode couplers and beam shapers that are durable, efficient, and can withstand high operating powers could feed directly into this market, as recognized by our project partners SPI Lasers.

Optical and Optoelectronic devices: A number of optical and optoelectronic fibre-based devices that can modulate, amplify and detect information will be developed and tested within the lifetime of this project. Such devices that are simple to produce, have high efficiencies, and are easy to integrate with existing infrastructures will have obvious economic and societal benefits to the ICT sector. Furthermore, by embedding the signal processing functions directly into the transport fibres, these components could result in improved energy efficiencies in ICT systems, helping to reduce the carbon footprint (which is currently larger than the airline industry).

Quantum Optics: The design and construction of ultra-low-loss fibre-integrated polarizers, detectors and correlated photon sources that can operate across the visible to near-infrared region would be of great interest for applications in future quantum information, computation and sensing systems. To maximize our impact in this area, we have already established a partnership with Prof. Faccio at the University of Glasgow, who is an expert in quantum technologies. As the platform technology matures, we will look to expand our work in this area by connecting with relevant Quantum Technology Hubs, several of which we already have links to (e.g., NQIT at Oxford and QuantIC at Glasgow), and their industrial partners.