Self-patterning light signals bright future for high-power lasers

Researchers at the Zepler Institute for Photonics and Nanoelectronics are investigating the self-patterning of light in multicore optical fibres as a route to scalable high-power lasers and all-optical signal processing.

An international collaboration led by Dr Massimiliano Guasoni is studying how beams in opposing directions arrange themselves into well-defined patterns, ideally suited for producing a high brightness single beam.

The research builds upon the University of Southampton's expertise in multicore optical fibres which, unlike traditional single cores, carry light through several strands to enhance the technology's properties. In each core, light can travel forward or backward, with simultaneous travel in both directions known as a counter-propagating configuration.

Dr Guasoni, who has recently formed the Multimode Photonics Group at the Optoelectronics Research Centre (ORC), says, "Preliminary studies carried out by the team members indicate that when the cores are sufficiently close, then strong coupling induced by the counter-propagating configuration may occur, such that the beams in each core organise themselves in to regular patterns.

"These results imply natural application in coherent beam combination, which refers to the ability to combine multiple independent light beams so as to obtain a single beam characterised by a high brightness and beam quality at the system output.

"This project aims to study the coupling dynamics between beams of different cores and to demonstrate its application in some important technological areas, ranging from high-power lasers through to telecommunications.

Unlike current state-of-the-art solutions, the researcher's; beam combination is achieved in an all-optical way that doesn't require complex and power-consuming electronic control systems.

The multidisciplinary research will progress over the next three years through over £660,000 of funding from the Engineering and Physical Sciences Research Council (EPSRC). Project partners include the Australian National University, Sapienza University of Rome and ORC spin-out company SPI Lasers.

During the project, scientists will design, fabricate and test bespoke multicore fibres where the proposed all-optical beam combination is exploited to build high-power optical sources and novel optical devices for the next generation internet. A general theoretical framework is also being developed that will find application not only in optics but also in other important disciplines, such as hydrodynamics.

Dr Guasoni says: "I am deeply grateful to Professor David Richardson, Professor Jayanta Sahu and our partner SPI Lasers. Their expertise and advice has been, to say the least, essential in order to shape the project proposal. In addition, internal review and discussions coordinated by Professor Andy Clarkson have been of utmost importance. In this respect, special thanks also goes to Dr Pier Sazio,Professor Anna Peacock and Dr Ben Mills."