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June 03, 2008

New Metamaterial a “Perfect” Absorber of Light

A team of scientists from Boston College and Duke University has developed a highly-engineered metamaterial capable of absorbing all of the
light that strikes it – to a scientific standard of perfection – they report in Physical Review Letters.


The team designed and engineered a metamaterial that uses tiny geometric surface
features to successfully capture the electric and magnetic properties of a microwave to the point of total absorption.

“Three things can happen to light when it hits a material,” says Boston College Physicist Willie J. Padilla. “It can be reflected, as in a mirror. It can be
transmitted, as with window glass. Or it can be absorbed and turned into heat. This metamaterial has been engineered to ensure that all light is neither reflected nor transmitted, but is turned completely into heat and absorbed. It shows we can design a metamaterial so that at a specific frequency it can absorb all of the photons that fall onto its surface.”

FURTHER READING
The Physics letters article is here

We present the design for an absorbing metamaterial (MM) with near unity absorbance A. Our structure consists of two MM resonators that couple separately to electric and magnetic fields so as to absorb all incident radiation within a single unit cell layer. We fabricate, characterize, and analyze a MM absorber with a slightly lower predicted A of 96%. Unlike conventional absorbers, our MM consists solely of metallic elements. The substrate can therefore be optimized for other parameters of interest. We experimentally demonstrate a peak A greater than 88% at 11.5 GHz.



1 comments:

Brock said...

It makes one wonder about designing a perfect solar cell - 100% conversion to electricity.