Research published in Nature Scientific Reports by Loughborough University’s Emergent Photonics Research Centre shows how a sparse layer of nanoparticles can make materials that produce terahertz radiation more efficient.
Terahertz radiation sits between microwaves and infrared on the electromagnetic spectrum and has a range of potential uses. It can ‘see’ through materials like clothing or plastic and detect chemical fingerprints, with applications in security screening, medical imaging, materials testing and wireless communications.
But existing devices are limited by how efficiently they can generate terahertz waves.
In the study, researchers added a layer of silica–gold nanoparticles to a spintronic material, which uses the spin of electrons to generate terahertz radiation. Despite covering only around 6% of the surface, the particles boosted the terahertz output by up to 1.6 times in experiments.
The team first used computer simulations to understand how the nanoparticles interact with light. They then assembled the material in the lab and used ultrafast laser pulses to determine how much terahertz radiation was produced.
Dr Vittorio Cecconi, Research Fellow at Loughborough University’s Emergent Photonics Research Centre, said: “One interesting and somewhat unexpected finding is just how sensitive the effect is: even a very small number of particles can make a difference in performance.
“These nanoparticles act like ‘light concentrators,’ focusing incoming laser energy into very small areas and making the device work more efficiently.”
The researchers say the approach offers a relatively simple and scalable way to improve terahertz technology, which could lead to better scanners, more precise testing tools, and faster wireless systems.
“Small changes at the nanoscale – far too small to see – can have a big impact on technology”, said Dr Cecconi.
“This work shows that by carefully designing these tiny structures, scientists can create new types of devices that are more powerful, efficient, and useful across wide range applications.”
The team now plans to explore new ways of arranging and designing the nanoparticles and improving the underlying materials to further increase performance.
Further information on the Emergent Photonics Research Centre can be found on the dedicated webpage.