Dec 9 2020
The pursuit of finding innovative, new techniques to manipulate the way light travels through electromagnetic materials has taken a new, peculiar twist.
As part of a groundbreaking research project, experts from the University of Exeter have created a new theoretical method to make light propagate through electromagnetic materials without being reflected.
The findings of the study could open the door for more efficient communications and wireless technology.
The focus of the project was to identify new types of electromagnetic materials through which light can travel in only one direction, without being reflected, using Maxwell’s equations. Published in the 1860s by physicist James Clerk Maxwell, the four crucial equations represent the way electric and magnetic fields move in space and time.
These equations form the basis of a majority of modern technology, ranging from optical and radio technologies to electric motors, radar and wireless communication.
Earlier, these new unusual materials had been understood using concepts that won the 2016 Nobel prize, concepts borrowed from an arbitrary area of mathematics called topology, which involves the study of properties of shapes that remain the same upon squeezing and molding them.
The innovative aspect of this study is that it has discovered the new electromagnetic materials with just a slight tweaking of the high-school concept of refractive index.
This discovery could simplify the development of materials in which light can propagate in only one direction and could, for example, be used to enhance telecommunication where information, which is lost when there is reflection, is transmitted as pulses.
The research has been described in Nature Physics, a renowned journal.
Our paper tests the limits of how light can behave by using Maxwell’s equations and electromagnetic theory to engineer exotic optical materials. I think the novelty here was neither using topology nor traditional methods of numerical simulation and optimization to find these materials.
Mitchell Woolley, Study Co-Author, University of Exeter
Woolley performed the research while studying Natural Sciences at the University of Exeter.
There is a lot of interesting physics and mathematics still to be found in understanding how light moves through matter. It’s very satisfying that the simple concept of the refractive index can be used in such unusual materials.
Dr Simon Horsley, Study Lead Author, University of Exeter
Horsley S A R & Woolley M (2020) Zero-refractive-index materials and topological photonics. Nature Physics. doi.org/10.1038/s41567-020-01082-2.