A study published in The Optical Society’s (OSA) journal Optica casts a whole new reflection on mirrors: Scientists from Sandia National Laboratories in Albuquerque, New Mexico, have created a non-shiny “mirror” that reflects infrared light using the magnetic properties of a non-metallic metamaterial.

“We have achieved a new milestone in magnetic mirror technology by experimentally demonstrating this remarkable behavior of light at infrared wavelengths. Our breakthrough comes from using a specially engineered, non-metallic surface studded with nanoscale resonators,” said Michael Sinclair, co-author on the Optica paper and a scientist at Sandia National Laboratories in Albuquerque, New Mexico, USA who co-led a research team with fellow author and Sandia scientist Igal Brener.

The resonators are based on the element tellurium, and are incredibly small – much smaller than the width of a human hair. They’re smaller, in fact, than even the wavelength of the infrared light they intend to reflect, which turns out to be a crucial factor.

“The size and shape of the resonators are critical,” explained Sinclair “as are their magnetic and electrical properties, all of which allow them to interact uniquely with light, scattering it across a specific range of wavelengths to produce a magnetic mirror effect.”

While nothing about conventional mirrors seems suspect to the human eye, there’s a lot going on at the particle level. Conventional mirrors reflect light by interacting with the electrical component of electromagnetic radiation. Beyond reversing the image, they also reverse light’s electrical field. This presents a problem at the mirror’s surface, where the opposing frequencies cancel each other out. For scientists, this means that things like quantum dots are unable to interact with light at the surface.

Magnetic mirrors, on the other hand, reflect light by interacting with its magnetic field, leaving its electrical field intact. Unfortunately, nothing in nature interacts with light in this way, prompting scientists to explore metamaterials like the one used to create the magnetic mirror.

“Our results clearly indicated that there was no phase reversal of the light,” remarked Sheng Liu, Sandia postdoctoral associate and lead author on the Optica paper.

Right now, the technology is largely experimental and works only with long, invisible wavelengths. However, further research into how to make it work with shorter wavelengths could open the doors for all sorts of applications.

“If efficient magnetic mirrors could be scaled to even shorter wavelengths, then they could enable smaller photodetectors, solar cells, and possibly lasers,” said Liu.