Light trapped in metamaterial for first time

MIT Technology Review : Electromagnetic waves were first trapped in the 1990s. The complex setups for doing so involve ultracold atomic gases, such as cesium and rubidium, and systems of lasers that take advantage of electromagnetically induced transparency . Now Toshihiro Nakanishi of Kyoto University in Japan and his colleagues have demonstrated a similar effect in a metamaterial made of repeating units of two variable capacitors. When both capacitors are set to the same frequency, incoming electromagnetic waves of that frequency are absorbed and trapped. Detuning the capacitors releases the waves and maintains the phase distribution of the absorbed waves. The team’s metamaterial is a three-layer deep proof-of-concept device that they successfully tested with microwaves. They believe that further work could produce a material that could trap optical frequencies or that could release waves of arbitrary shape and polarization. Those capabilities could be useful in information storage and quantum optics.