Institute of Communications and Connected Systems


UCL researchers move free-space optical comms closer to a ubiquitous, commercial technology

19 January 2021

Researchers have this month published work that will provide essential tools to the community in the development of Luminescent Solar Concentrators for use in free space optical communications applications

Image of female standing under light with 0s and 1s streaming down to her device, in-lay shows bright fluorescing squares of material

Author: Dr Robert Thompson, Institute Manager

Optical Communications | VLC | LSC

A multidisciplinary team of researchers from UCL has recently published work that provides essential analytical models and experimental tools for the development of Luminescent Solar Concentrators for use in high-speed optical sensing and communication applications.

Luminescent Solar Concentrators (LSCs) are a technology that offers an unprecedented ability to collect, concentrate and direct light to a desired location. These properties have, to date, made LSCs an excellent candidate for the large-area harvesting of light in applications such as renewable energy.

Recently, these beneficial characteristics of LSCs have made them a promising candidate for use in free-space optical-communications, however, an LSC's ability to preserve high-speed variations in the properties of the received light must be understood and optimised for successful integration in applications such as LIDAR, LiFi and optical Signal Processing.

As a photonic based technology, LSCs utilise fluorescence, the absorption and reemission of photons, to trap light in the host material. Trapped light is then able to travel long distances within the materials, similar to propagation of light within an optical fibre.

The slow timescales of fluorescence events and multiple reabsorptions of photons can have a detrimental impact on maintaining the high-speed variation in light utilised for communication applications.

Publishing in the nature journal, Light: Science and Applications, the team of researchers, including members of the UCL Institute of Communications and Connected Systems (ICCS), explore these dynamic effects of LSCs and associated systems, an area of work that to date has had little focus from the community.

The team's work has provided essential theoretical and experimental tools to fully understand these dynamic processes within LSCs, unlocking their potential for the entire community. 

Speaking about the impact of the work, lead author Dr Mark Portnoi said:

"We can now model large scale systems, predicting and optimising their properties without even fabricating the devices. The impact should see substantially reduced development cycles at lower costs, accelerating advances and innovations in the area.
"In our group alone we expect to explore the work for applications in high-speed, wide-field-of-view optical detectors; optical signal processing; LIDAR and real-time sensors, to name just a few."

To enable the success of the work required a multi-university and multi-disciplinary team. Within ICCS, photonic applications expertise were provided by Professor Ioannis Papakonstantinou, head of the UCL Photonic Innovations lab, along with members of his group. Professor Izzat Darwazeh, director of ICCS provided expertise on communication system design and modelling. 

The team also included the groups of Dr Thomas MacDonald from Imperial College London, Dr Paul Haigh from Newscastle University, and Prof Ivan Parkin of UCL Chemistry.

Speaking on the multidisciplinary effort and impact of the work Professor Papakonstantinou, head of the Photonic Innovations lab in the UCL Department of Electronic and Electrical Engineering, said:

"Luminescent Solar Concentrators are complex photonics systems which only recently we have started understanding properly. Harnessing their full potential requires collaboration across many interdisciplinary areas: photonics, electronics, chemistry and material synthesis.
"Our work here is testament to the collaborative approach all of our colleagues take to their work and the importance of engaging outside of our respective fields to enable innovation." 

The publication was a result of work supported by the EPSRC project MARVEL, an EPSRC Doctoral Training Award and the European Research Council Starting Grant IntelGlazing.