Ultrafast lasers use ‘lantern light’ to reveal secrets of the universe
Researchers at the Institute of Photonics and Quantum Sciences (IPaQS) at Heriot-Watt University have been using ultrashort pulses of laser light to make ‘photonic lanterns’ – optical circuits that could revolutionise how telescopes are used to observe the universe.
Dr Robert Thomson, an expert in ultrafast laser inscription at Heriot-Watt’s Institute of Photonics and Quantum Sciences (IPaQS), has developed a new device technology for future telescopes to improve analysis of captured celestial light so that more scientific information can be gleaned from it.
His work, which is funded by the European Union and the UK Science and Technology Facilities Council (STFC), may have applications, for instance, in the proposed €1bn European Extremely Large Telescope (E-ELT).
Thomson’s devices are made using ultrashort laser pulses, each only about 0.0000000000001 (one ten- trillionth) of a second long to inscribe laser-modified ‘tracks’ into a substrate material. The tracks act as optical circuits – photonic lanterns – and guide photons (particles of light) in much the same way as electronic circuits guide electrons.
“Developing new instrument concepts for large-scale telescopes and space-based instruments can be achieved using photonic technologies which are the optical equivalent of electronics and enable the flow of light to be precisely controlled and shaped, said Thomson.
“Compared to the traditional optics used in telescopes, such as mirrors and lenses, photonic technologies have the potential to be more efficient and reduce costs. With just one night on a world-leading telescope costing tens of thousands of pounds, it is essential that the instruments on the telescope deliver the maximum scientific output. This is where ‘astrophotonics’ may have the edge over conventional optical technologies.
“By reducing the amount of light that is ‘lost’, and by more efficiently controlling the light that is collected, photonic devices may help increase what can be observed on a telescope, meaning we should be able to learn more about the nature of the universe around us.”
Photonic lantern technology is already being commercialised for next-generation data communications by Optoscribe Ltd, a spin-out from Heriot-Watt, co-founded by Thomson and his colleagues.