The photonics pioneer shaping scientific discovery and data comms with light

Almost all information travels around the world in the form of light pinging along optical fibres. We’ve got photonics – a discipline that harnesses light’s remarkable properties – to thank for that, along with LiDAR, laser eye surgery, computer mice, remote controls, and the laser manufacturing that made your car and TV. The field employs as many people in the UK as automotive or aerospace engineering, according to an industry group.

Photonics is “foundational to our society”, says Professor Robert Thomson FREng, a photonics engineer at Heriot-Watt University and a 2026 winner of the Princess Royal Silver Medals. The engineer is recognised for his seminal inventions that are enabling fibre-optic networks to keep pace with the ever-increasing amount of data we send through them, as well as more leftfield advances in astronomy and medical imaging.

Thomson’s own path into the field involved a healthy dose of pure circumstance. “I would like to say I was born with a strong instinct for photonics,” he jokes. But it was studying physics at Heriot-Watt – one of the UK’s top centres for photonics research – that set him on the photonics path.

His research career has revolved around solving practical problems with photonics. These have ranged from increasing how much data a single optical fibre can carry, to extracting more information from starlight collected from astronomical telescopes and tracking medical devices deep in the body.

Making the most of telescope signals

Thomson’s first fellowship focused on applying photonics to astronomy. The signals from telescopes are fundamentally unlike those you would normally see in photonics’ more natural application areas, such as telecoms and defence, explains Robert. “[Astronomy] pushes you to think about the photonics in a very different way.”

For example: our internet infrastructure is underpinned by optical fibres that can stretch for thousands of kilometres. They’re largely engineered to force tightly focused laser light along a single path, called a mode. This approach minimises losses and helps the signal remain uncorrupted, keeping the internet running smoothly without glitches or drops in speed.

By contrast, a ground-based telescope simultaneously receives a multitude of faint and diffuse signals from stars, planets, and galaxies across the night sky, which have been scrambled by the Earth’s atmosphere en route. Naturally, it is messy, with light travelling in many modes.

Photonic technologies can be used to enable precise measurements that tell us more about, say, distant galaxies and exoplanets. To do so this multimode optical soup must be converted into clean single-mode signals. Thomson and his colleagues developed a device called an integrated photonic lantern – somewhat like an adapter for light – to achieve this.

It is just one of several low-cost, compact and easily mass-produced photonic technologies that Thomson has developed to help astronomers efficiently manipulate, transport and analyse light.

“If you're building something like the ELT [Extremely Large Telescope], a 40-metre class telescope, you want to be able to maximise its scientific output. You don't want to throw away light,” says Thomson. Such devices help researchers “maximise how much you learn per pound” – key when the cost of astronomy programmes is, well, astronomical.

More bandwidth and new horizons

In a world of data hungry applications such as AI, “we’re running out of bandwidth,” he says. “The question is, how do we get more?”

Putting more conventional optical fibres in the ground or data centre doesn’t scale well; engineers have already exploited every other property of light to pack data into fibres – the last to capitalise on was spatial modes, he explains.

The integrated photonic lantern would come in handy here too, allowing more spatial modes to be funnelled into the same optical fibre – hence enabling the fibre to carry more data. Thomson co-founded a spinout company in 2010, Optoscribe, to commercialise this and other inventions.

With the amount of money and investment involved in data centres, Thomson explains, there's a drive to use photonics to maximise the processing power of these facilities. And in 2022, semiconductor giant Intel acquired Optoscribe – a natural addition to its portfolio of technologies supporting data centres and communications infrastructure.

Of the many bright spots for the future of photonics, one of the emerging areas Thomson is most excited about is how advanced optical fibre technologies could help us see inside our bodies with greater precision than ever before.

Today, the endoscopes that allow us to look at internal organs contain bundles of thousands of optical fibres, that transmit light – and thus an image – from one end to the other. To preserve the image, the fibres must be kept separated to stop light tunnelling between them. The downside is that this limits the resolution.

Thomson’s group is applying individual multimode fibres to the problem. These scramble the light, but in a predictable way that can be un-scrambled. It means the light can be cleanly transmitted, like in a fibre bundle, but at a much higher resolution. If successful, it would be akin to putting a microscope inside the body, with the resolution of a few hundred nanometres.

“Our understanding of how to manipulate light propagation in these fibres has only really taken off in the last 10 or so years,” says Thomson. “I think that opens up a new window on human biology, in the future, for applications like viewing drug target engagement inside the body, doing proper microscopy, really imaging cells and pathogens at ultra-high resolution inside the body.”

For someone who took some convincing to become an academic, it is yet another fascinating avenue to take advanced photonics down. “I was never going to be a theoretical physicist,” he says, “but I’m passionate about problem-solving.”