As in Alice's journey through the looking-glass to Wonderland, mirrors in the real world can sometimes behave in surprising and unexpected ways, including a new class of mirror that works like no other. As reported today in The Optical Society's (OSA) new journal Optica, scientists have demonstrated, for the first time, a new type of mirror that
forgoes1 a familiar shiny
metallic2 surface and instead reflects
infrared3 light by using an unusual magnetic property of a non-metallic metamaterial.
By placing nanoscale
antennas4 at or very near the surface of these so-called "magnetic mirrors," scientists are able to capture and harness electromagnetic radiation in ways that have
tantalizing5 potential in new classes of chemical
sensors6, solar cells, lasers, and other optoelectronic devices.
"We have achieved a new
milestone7 in magnetic mirror technology by experimentally demonstrating this
remarkable8 behavior of light at infrared
wavelengths9. Our breakthrough comes from using a
specially10 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.
These nanoscale cube-shaped resonators, based on the element tellurium, are each
considerably11 smaller than the width of a human hair and even tinier than the wavelengths of infrared light, which is essential to achieve magnetic-mirror behavior at these incredibly short wavelengths.
"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,
scattering12 it across a specific range of wavelengths to produce a magnetic mirror effect."