In new optical research published in Optica on Friday, October 17th, scientists have demonstrated a new class of mirror that captures electromagnetic radiation for the first time. This new optical technology could lead to a variety of advances in chemical sensors, solar cells, lasers and other optoelectronic devices.
The new magnetic mirror does not have the familiar shiny metallic surface of regular mirrors, and instead reflects infrared light by using a magnetic property of a non-metallic metamaterial.
The researchers placed nanoscale antennas at or very near the surface of these so-called “magnetic mirrors” to capture electromagnetic radiation in ways that have great potential for the development of new types of chemical sensors, solar cells and related devices.
Statements from researchers
“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,” explained Michael Sinclair, co-author of the Optica paper and a scientist at Sandia National Laboratories who co-led a research team with fellow Sandia scientist Igal Brener.
“The size and shape of the resonators are critical, 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,” Sinclair noted.
“Our results clearly indicated that there was no phase reversal of the light,” commented Sheng Liu, Sandia postdoctoral associate and lead author on the Optica paper. “This was the ultimate demonstration that this patterned surface behaves like an optical magnetic mirror.”
More about magnetic mirrors
The cube-shaped resonators used in the new magnetic mirrors use tellurium. The resonators are even smaller than the width of a human hair and thinner than the waves of infrared light.
The Sandia researchers plan to investigate how other materials can also display magnetic mirror behavior at even shorter wavelengths.
“If efficient magnetic mirrors could be scaled to even shorter wavelengths, then they could enable smaller photodetectors, solarcells, and possibly lasers,” Liu pointed out in concluding.