New zero-index
material made of silicon pillar arrays embedded in a polymer matrix
and clad in gold
film creates a constant phase of light, which stretches out in infinitely
long wavelengths. (Illustration by Credit: Peter
Allen/Harvard SEAS)
LIGHT GOES INFINITELY FAST WITH NEW ON-CHIP MATERIAL
(October 20, 2015) Electrons
are so 20th century. In the 21st century, photonic devices, which use light to
transport large amounts of information quickly, will enhance or even replace
the electronic devices that are ubiquitous in our lives today. But there’s a
step needed before optical connections can be integrated into
telecommunications systems and computers: researchers need to make it easier to
manipulate light at the nanoscale.
Researchers at the Harvard John A. Paulson School of
Engineering and Applied Sciences (SEAS) have done just that, designing the
first on-chip metamaterial with a refractive index of zero, meaning that the
phase of light can travel infinitely fast.
This new metamaterial was developed in the lab of Eric
Mazur, the Balkanski Professor of Physics and Applied Physics and Area Dean for
Applied Physics at SEAS, and is described in the journal Nature Photonics.
“Light doesn’t typically like to be squeezed or manipulated
but this metamaterial permits you to manipulate light from one chip to another,
to squeeze, bend, twist and reduce diameter of a beam from the macroscale to
the nanoscale,” said Mazur. “It’s a remarkable new way to manipulate light.”
Although this infinitely high velocity sounds like it breaks
the rule of relativity, it doesn’t. Nothing in the universe travels faster than
light carrying information — Einstein is still right about that. But light has
another speed, measured by how fast the crests of a wavelength move, known as
phase velocity. This speed of light increases or decreases depending on the
material it’s moving through.