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.
