Dielectric Metamaterial is Dynamically Tuned by Light

Researchers at Duke University have built the first metal-free, dynamically tunable metamaterial for controlling electromagnetic waves. The approach could form the basis for technologies ranging from improved security scanners to new types of visual displays.

A metamaterial is an artificial material that manipulates waves like light and sound through properties of its structure rather than its chemistry. Researchers can design these materials to have rare or unnatural properties, like the ability to absorb specific ranges of the electromagnetic spectrum or to bend light backward.

In the new technology, each grid location contains a tiny silicon cylinder just 50 microns tall and 120 microns wide, with the cylinders spaced 170 microns apart from one another. While silicon is not normally a conductive material, the researchers bombard the cylinders with a specific frequency of light in a process called photodoping. This imbues the typically insulating material with metallic properties by exciting electrons on the cylinders’ surfaces.

Read more at Duke University

Image Credit: Duke University

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