New Sandia Mirror Isn’t Shiny: Instead It Reflects Infrared Light Using a Metamaterial

An optical wave’s reflection from metal arises from strong interactions between the optical electric field and the metal’s free carriers and is accompanied by a phase reversal of the reflected electric field.

A far less common route to achieving high reflectivity exploits strong interactions between the material and the optical magnetic field to produce a “magnetic mirror” that does not reverse the phase of the reflected electric field.

In their paper, “Optical magnetic mirrors without metals” in Optica, the authors report on developing a new type of mirror that isn’t shiny, and instead reflects infrared light by using a magnetic property of a nonmetallic metamaterial.

At optical frequencies, the magnetic properties required for strong interaction can be achieved only by using artificially tailored materials. The team experimentally demonstrated the magnetic mirror behavior of a low-loss all-dielectric metasurface at infrared optical frequencies through direct measurements of the phase and amplitude of the reflected optical wave.

The enhanced absorption and emission of transverse-electric dipoles placed close to magnetic mirrors can lead to exciting new advances in sensors, photodetectors, and light sources.