Start date: October 2019
Duration: 3.5 yrs
Conventional optical communications is based on fibre-optic networks operating in the near-infrared. This is now beginning to be supplemented by free-space optical communications which are being explored in a range of wavelengths and formats. Deep ultraviolet light (in the 240-280nm waveband) can now be generated directly by gallium nitride semiconductor based light emitting diode (LED) technology. Such wavelengths scatter strongly in the atmosphere and thus are in a ‘solar blind’ region where light from the sun is filtered out. This combination of scattering in the absence of solar background means that it is possible to use extremely low levels of light, down to the single photon regime, in conjunction with solid-state photon counting detectors. At these received power levels, processing and manipulating optical signals become statistical in nature, requiring new technologies and methodologies to be developed. Applications scenarios include ‘seeing round corners’, underwater communications, and communicating between satellites at wavelengths that cannot be observed from the ground.
The Institute of Photonics is a recognized international pioneer of micro-LEDs, arrays of micron-sized light-emitting diodes constituting a new high-brightness microdisplay and backlighting technology – being applied, for example, to advanced virtual and augmented reality headsets. These displays interface to CMOS electronics and can be modulated at very high (megahertz) frame rates and communicate data at gigabits/second. Such rapidly modulated patterned light enables a form of optical projection called structured illumination with applications in indoor navigation, spatially modulated data communications, single pixel imaging and bio-imaging. These GaN microdisplays are extremely energy efficient and can be run with ultra-low photon flux. By coupling these displays with high speed single photon avalanche detector (SPAD) arrays, we have demonstrated a unique method for the spatio-temporal encoding of information at the few photon level that is extremely robust to noise. Initial demonstrations of simple data transmission, with efficiencies in the order of 30 photons per bit, have already garnered significant interest from the scientific and industrial communities.
This project will develop novel formats of these devices operating at deep ultraviolet wavelengths (<280nm). At these wavelengths, the earth’s atmosphere is highly scattering and opaque to solar radiation. This offers the possibility of ‘communicating around corners’ at very low light levels or communicating between satellites at wavelengths that cannot be seen from the ground. It also offers novel forms of microscopy system with high resolution and sensitivity to surfaces and interfaces. The project will encompass optical systems design and development, electronic driver and software coding and sparse data signal processing techniques. The PhD student will have access to state-of-the-art, custom LED and SPAD array devices, optical characterisation facilities and software tools, and will contribute to the UK’s national programme on Quantum Technologies.
Institute of Photonics:
The Institute of Photonics (IoP), part of the Department of Physics, is a centre of excellence in applications-oriented research at the University of Strathclyde - the Times Higher Education UK University of the Year 2012/13 and UK Entrepreneurial University of the Year 2013/14. The Institute’s key objective is to bridge the gap between academic research and industrial applications and development in the area of photonics. The IoP is located in the £100M Technology and Innovation Centre on Strathclyde’s Glasgow city centre campus, where it is co-located with the UK’s first Fraunhofer Research Centre. Researchers at the IoP are active in a broad range of photonics fields under the areas of Photonic Devices, Advanced Lasers and Neurophotonics, please see: http://www.strath.ac.uk/science/physics/instituteofphotonics/ourresearch/
How to apply
To enter our PhD programme applicants require an upper-second or first class BSc Honours degree, or a Masters qualification of equal or higher standard, in Physics, Engineering or a related discipline. Full funding, covering fees and stipend, is available for UK and EU nationals only.
Applicants should send a CV to [email protected]