Optical scientists have found a new way to significantly increase the power of fibre lasers while maintaining their beam quality, making them a future key defence technology against low-cost drones and for use in other applications such as remote sensing.
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 but without deteriorating the beam quality so that it can focus on distant targets.
Co-first author Dr Linh Nguyen, a researcher at UniSA’s Future Industries Institute, says the new approach will allow the industry to continue squeezing out extremely high power from fibre lasers, make 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,” Dr Nguyen says.
“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.”
In delivering an asymmetric advantage this advanced capability has the potential to provide a strong deterrent effect, aligning well with the objectives of the Defence Strategic Review and AUKUS Pillar 2 objectives.
Dr Ori Henderson-Sapir, project investigator at the UoA’s Institute for Photonics and Advanced Sensing, says that 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.”
The researchers have demonstrated the technology in fibre lasers and will report their findings at Photonics West, the premium international conference on photonics technology, in early 2024.
Mitigating stimulated Brillouin scattering in multimode fibers with focused output via wavefront shaping is published in Nature Communications.
