New Gold-Plated Silicon Array Can Cleverly Control Light

A previous version of this article mistakenly reported that light hitting the chip was transmitted to the other side instantaneously. That would violate the laws of physics, of course. We regret the error.

Materials scientists have developed a new chip made with a metamaterial that can manipulate light in clever new ways. The key is in the metamaterial’s refractive index, or how it manipulates light.

A rendering of the zero-index metamaterial chip

Water, for example, has a refractive index of 1.33, which makes a straw look disjointed in a glass of water. But the metamaterial created by Eric Mazur’s lab at Harvard University has a refractive index of zero. If you shine a light on the surface at a 90˚ angle—perfectly perpendicular, in other words—it will turn that beam 90˚ and propagate it along the material.

There, the structure of the material allows another curious thing to happen: The light doesn’t produce its typical sinusoidal wave pattern, it’s straight as an arrow. Technically it’s still a wave, just one that’s stretched out to infinity.

That prevents interference between two different phases of light, and the unprecedented control the metamaterial offers gives scientists new ways to shoot light signals around the chip in a coordinated fashion.

Here’s Olivia Goldhill, reporting for Quartz:

We won’t see light-based computers yet, as there are still several obstacles to address, but Mazur and his team have overcome a key challenge. “Usually, light needs to be handled very carefully and squeezed very slowly,” says Mazur. “With our material, you relax those constraints completely. You can bend the light, squeeze it, twist it.”

There still lots to be worked out, including refining the fabrication process and tying the various components of an optical chip together into one package. But the zero-index metamaterial chip is a clever solution that could help pave the way for super-fast optical computing.