Equations developed by physicist James Clerk Maxwell have helped to reveal how crystals can be manipulated to produce a distinctive form of lightwave. Researchers from the University of Edinburgh and Pennsylvania State University made the discovery by analyzing how light waves interact with certain naturally occurring or man-made crystals. The researchers found that a previously unknown type of lightwave, recently named the Dyakonov-Voigt wave, was produced at the interface where the crystals meet another material, such as oil or water. Dyakonov-Voigt waves can be produced only by using certain types of crystals whose optical properties depend on the direction in which light passes through them. Dyakonov-Voigt waves decay as they move away from the interface and travel only in a single direction. Other types of so-called surface waves decay more quickly and travel in multiple directions. “Dyakonov-Voigt waves represent a step forward in our understanding of how light interacts with complex materials and offer opportunities for a range of technological advancements,” researcher Tom Mackay said. The research was published in Proceedings of the Royal Society A (https://doi.org/10.1098/rspa.2019.0317).