Authenticating in 3D Polarisation

A team of scientists, led by Prof Xianzhong Chen from the School of Engineering and Physical Sciences, Heriot-Watt University, UK, and Prof Shuang Zhang from the Department of Electronic & Electrical Engineering, University of Hong Kong, China, have developed an optical metasurface to create colour-selective 3D polarisation structures.

In a paper ¹ published in ‘Light: Science & Applications’, the scientists describe how polarisation, as a central concept to the understanding of optics, has found many applications, including in the field of quantum science, product authentication, and even in our daily lives, in the form of polarised sunglasses and 3D cinema.

While there have been many advances made in the theoretical understanding of 3D polarisation structures, experimental research has not followed at the same rate, explains the paper.

This is essentially due to the technical challenges of creating 3D polarisation profiles with conventional methods (ie. light refraction and propagation), which are only really able to create 2D structures in a transverse plane. As a result, only a small number of 3D structures have so far been generated, but their practical application has been limited by cost, complexity, and the large size of the structures.