Irish physicists researching photonics have made a new discovery that will profoundly impact our understanding of the fundamental nature of light and possibly transform the future of communications.
The discovery by Prof Paul Eastham from Trinity College Dublin’s School of Physics and Prof John Donegan from the Science Foundation Ireland-backed CRANN research centre could have a major impact in terms of fibre-optic communications.
One of the measurable characteristics of light is known as angular momentum.
Up until now, in all forms of light, the angular momentum was thought to be multiples of Planck’s constant – the physical constant that sets the scale of quantum effects.
But the professors were able to discover a form of light where the angular momentum could be a fraction rather than a multiple.
‘What I think is so exciting about this result is that even this fundamental property of light, that physicists have always thought was fixed, can be changed’
– PROF PAUL EASTHAM, TCD
Their findings were published in the online journal Science Advances.
Donegan said that his research focuses on the study of light at nanometre scale.
“A beam of light is characterised by its colour or wavelength and a less familiar quantity known as angular momentum. Angular momentum measures how much something is rotating.
‘Our discovery will have real impacts for the study of light waves in areas such as secure optical communications’
– PROF JOHN DONEGAN, CRANN
“For a beam of light, although travelling in a straight line, it can also be rotating around its own axis. So, when light from the mirror hits your eye in the morning, every photon twists your eye a little, one way or another.
“Our discovery will have real impacts for the study of light waves in areas such as secure optical communications.”