New technique boosts fibre laser power

Researchers from the University of South Australia (UniSA), the University of Adelaide (UoA) and Yale University have demonstrated the potential use of multimode optical fibre to scale up power in fibre lasers by three to nine times without deteriorating the beam quality, so that it can focus on distant targets. The research findings, published in Nature Communications, could make fibre lasers a future key defence technology against low-cost drones and useful for other applications such as remote sensing.

Co-first author Dr Linh Nguyen from UniSA said the new approach will enable the industry to continue squeezing out high power from fibre lasers, making them more useful for the defence industry and for remote sensing applications and gravitational wave detection.

“High-power fibre lasers are vital in manufacturing and defence, and becoming more so with the proliferation of cheap, unmanned aerial vehicles (drones) in modern battlefields. A swarm of cheap drones can quickly drain the missile resource, leaving military assets and vehicles with depleted firing power for more combat-critical missions. High-power fibre lasers, with their extremely low-cost-per-shot and speed of light action, are the only feasible defence solution in the long run. This is known as asymmetric advantage: a cheaper approach can defeat a more expensive, high-tech system by playing the large number,” Nguyen said.

In delivering an asymmetric advantage, this advanced capability could provide a strong deterrent effect, aligning with the objectives of the Defence Strategic Review and AUKUS Pillar 2 objectives. Dr Ori Henderson-Sapir, project investigator at the UoA Institute for Photonics and Advanced Sensing, said Australia has a long history of developing innovative fibre optics technologies. “Our research launches Australia into a world-leading position to develop the next generation of high-power fibre lasers, not only for defence applications, but to aid new scientific discoveries,” Henderson-Sapir said.

The researchers demonstrated the technology in fibre lasers and will report their findings in Photonics West, in early 2024.

Image credit: iStock.com/style-photography