* The author is part of the community of readers of La Vanguardia
I have interpreted pieces of glass for La Vanguardia Readers' Photos, inspired by perfume bottles, with the aim of interpreting the idea of unidirectional glass to create windows that allow us to clearly see what is outside without anyone seeing what is happening inside.
More than an idea, it is almost a reality after researchers at Aalto University in Finland have managed to create an optical metamaterial that can lead to unidirectional crystal. It would allow, for example, to create voyeur-proof windows and make it unnecessary for us to use curtains at home (unless we want to do so simply for aesthetics).
Unlike natural materials, with fixed electromagnetic properties, metamaterials allow these properties to be modified to design specific functionalities.
To give us an idea, the response of a traditional material to electric and magnetic fields (and, therefore, to light), is determined by the arrangement of its atoms. But, in the case of the new metamaterial created by researchers at Aalto University, it takes advantage of the non-reciprocal magnetoelectric effect (NME), which offers control over the flow of light.
This is specified in the study Tellegen optical metamaterial with spontaneous magnetization published in the journal Nature Communications. "We propose a three-dimensional metamaterial with an isotropic and resonant Tellegen response in the visible frequency range," the researchers explain.
"The metamaterial is formed by bimaterial nanocylinders randomly oriented in a host medium," they detail, and "the proposed metamaterial does not require external magnetic polarization and operates with the spontaneous magnetization of the nanocylinders."
Be that as it may, this novel optical metamaterial can make one-way glass a reality and create windows that allow us to see what is outside without anyone being able to see what is happening inside. Ideal for avoiding onlookers without preventing us from looking at ourselves.
