Spin-controlled Photonics Could Streamline Communications Components

A new class of metamaterials with the potential to control the spread of light more easily could help in the design of more streamlined components for communications technology.

The components used today in communications technology are bulky and difficult to integrate with microelectronic circuits. However, in the new class of metamaterials developed at Technion-Israel Institute of Technology, the standard characteristics of waves can be altered so the spread of light can be controlled more simply.

Thermal radiation modes emitted by spin-optical metamaterial based on inversion asymmetric kagome lattice. The illuminated color spirals symbolize the photon helicity-split due to optical Rashba effect. False-colored electric field distribution near the metasurface obtained by numerical simulation. The design of photonic metasurface symmetries via geometric gradient of the optical antenna patterns provides a route to control light-matter interaction at the nanoscale. Images courtesy of Technion-Israel Institute of Technology.

Inspired by the design of metallic nanoantennae found in nature, Nir Shitrit and colleagues created an anisotropic material — one that does not behave the same way when measured in different directions. Another critical feature is that the material does not exhibit characteristic inversion symmetry on its surface.

Shitrit and colleagues observed that electromagnetic waves propagated in a nontypical way in their new material; waves with different circular polarization had different and distinct dispersion patterns. Typically, dispersion is not linked to polarization, but in this class of material, it is shown to be polarization-dependent.

Identification of polarization-dependent waves lays the groundwork for controlling light-matter interactions at the nanoscale in future communications technology.

The research is published in Science (doi: 10.1126/science.1234892).