In today’s world, the fight against counterfeiting is more critical than ever. Counterfeiting affects about 3% of global trade, posing significant risks to the economy and public safety. From fake pharmaceuticals to counterfeit currency, the need for secure and reliable authentication methods is paramount. Authentication labels are commonly used – such as holograms on bank notes and passports – but there is always a need for new unfalsifiable technologies.
This is where new groundbreaking research recently published in Applied Sciences comes into play. Led by a team of scientists from Oxford University, the University of Southampton, and Diamond Light Source, the UK’s national synchrotron, the work focuses on developing a new technology for writing and reading covert information on authentication labels. This technology leverages the unique properties of Ge2Sb2Te5 thin films, which can change their structure when exposed to specific types of laser light. By using circularly or linearly polarised laser light, the researchers can encode hidden information in these thin films. This information can then be revealed using a simple reading device, making the technology both advanced and accessible. The paper is called ‘Application of Photo-Induced Chirality in Covert Authentication’ and explains how photo-induced chirality in Ge2Sb2Te5 thin films can be exploited to improve authentication.
The significance of this research lies in its potential applications. Authentication labels are essential in various industries, including pharmaceuticals, electronics, and currency. The ability to encode and read covert information securely can help prevent counterfeiting and ensure the authenticity of products. Moreover, the technology’s reliance on existing manufacturing methods makes it a practical solution for widespread use.
To create these new authentication labels, the authors deposited 55nm thick film on a disk substrate. After that, author, Dr Konstantin Borisenko, Research Computing Administrator at University of Oxford explained,
We ‘wrote’ a predesigned pattern of spots using a laser and a polariser. Then we used the B23 beamline at Diamond Light Source to ‘read’ the film using circular dichroism (CD), a type of spectroscopy, and recorded the CD spectra in transmission mode.
Read more on Diamond website
