Two-dimensional Photonics Fabrication Facility

Remarkable discoveries and advances in two-dimensional semiconductors beyond graphene, designer meta-surfaces, and integrated quantum or non-linear photonic devices are driving a revolution in optoelectronic and photonic technologies. The Two-Dimensional Photonics Fabrication Facility at Heriot-Watt University will facilitate this revolution in the UK with a user facility unique to the UK landscape. The centrepiece instrument, a "maskless" direct write laser, is a lithographic tool to rapidly fabricate large scale but bespoke 2D photonic devices with novel functionalities. The maskless laser writer bridges the gap in lateral resolution and write speed between electron beam lithography and conventional photolithography to enable rapid fabrication of nanoscale photonic devices over large areas. The unique lithography system will be augmented by an electron beam evaporator enabling deposition of high-quality metals and dielectrics with nanometre precision onto devices lithographically defined by the direct write laser. Finally, for the ultimate in thin-film, surface and materials metrology, a spectroscopic imaging ellipsometer will be used. This unique instrument is crucial for characterization, either pre- or post-fabrication by the lithographic tool, of emerging two-dimensional semiconductor devices. The facility will be integrated into the newly refurbished cleanroom at Heriot-Watt University housing an array of complementary equipment. This will underpin emerging 2D photonics research for numerous PhD students and early career and established academics at HWU and across the UK. The facility strongly leverages existing excellence in photonics research within the Institute of Photonics and Quantum Sciences at Heriot-Watt and a large cohort of prospective facility users exist within two EPSRC centres for doctoral training, two UK Quantum Technology Hubs, and the EPSRC Centre for Innovative Manufacturing in Laser Based Production Processes.
Four specific research thrusts will be enabled by the facility:
1. Two-dimensional quantum photonics based on recently discovered quantum emitters embedded in 2D semiconductors 'beyond graphene' that can produce a remarkably wide range of electronic and optical properties. Novel devices will be fabricated to drive forward this exciting emergent quantum photonic platform.
2. Ultrathin optical devices made from metasurfaces, which are two-dimensional metamaterials exhibiting unusual optical properties. The facility will enable rapid fabrication of large-scale metasurfaces to create 'flat' optics for potential applications (e.g. microscopes, cameras, displays, and mobile phones) across a range of frequencies (e.g. visible - terahertz).
3. Fabrication of integrated photonics devices including optimized single photon focal plane arrays, microlens arrays, mosaic filters, low-loss waveguides, and high-quality cavities for quantum, non-linear, and ultra-fast photonics.
4. High-resolution characterization for a wide-range of novel thin film and two-dimensional semiconductor materials and devices.

The Two-Dimensional Photonics Fabrication Facility at Heriot-Watt University is a user-facility designed to accelerate research and innovation in 2D photonics by developing fabrication tools and technical capability unique within the UK. The research thrusts enabled by the facility will enhance substantial national investments in 2D materials, quantum technologies, photonics, material manufacturing and characterization, and early-stage researcher training. This vision is shared by a large cohort of researchers within the Institute of Photonics and Quantum Sciences at Heriot-Watt and numerous potential end-users throughout UK academia and industry. The facility's large spectrum of academic users will underpin knowledge creation across a wide spectrum of research directions. One direction targeted in the first few years of the facility is to develop novel heterostructure (stacks consisting of different layers) opto-electronic and quantum devices based on 2D semiconductors and to share the fabrication expertise with the world-leading UK community in 2D semiconductors. A significant goal is to drive forward a new platform for quantum photonics that can then be made available to the UK National Quantum Technology Programme. Another goal is to fabricate metasurfaces over large scales that can help bridge the 'valley - of - death" between research and commercialization of new 'flat-optics' based photonic devices. Another impact will be on the development of technologies that rely on imaging in very low light environments by fabricating integrated hybrid single photon focal arrays with micro-lenses or additional functionalities for increased efficiencies and capabilities in 'single-photon depth imaging'. Another aspect of the work will be to fabricate photonic chips with integrated waveguides and cavities that can route single photons or achieve optical non-linearity. Such integrated photonic chips would underpin new quantum technologies, ultra-fast lasers, or ultra-high resolution metrology. In addition to unique fabrication capabilities, the facility will boast a spectroscopic imaging ellipsometer that will become a highly coveted work-horse tool in thin film metrology for researchers working novel thin films that can lead to new types of spintronic devices or materials that take advantage of topological quantum states or thin films that can lead to single photon quantum optics. Each of these research directions has potential to impact future technologies that exploit the laws of quantum mechanics. Industrial impact beneficiaries range from facility users interested in rapid prototyping of devices to those keen to characterize propriety thin-film based devices with of high-resolution ellipsometer. The UK Centre for Innovative Manufacturing in Laser Based Production Processes and its 35 partner companies will also benefit from access to this unique facility. In summary, the Two-Dimensional Photonics Fabrication Facility will sustain the UK's leading position in several research fields and, because of the rapid prototyping and large-scale sample fabrication capabilities, will help translate the research advances into economic success in the next decade. Early-career researchers training and researching in the facility will become a source of highly skilled workers for companies at the cutting edge of technology, in photonics and quantum technologies. Through public outreach, which several in our team excel at, the capability of the facility will enthuse future scientists and engineers.