Science
News: Topological insulators, first proposed in 2005, allow
electrons flowing along their surfaces to pass obstacles with
no difficulty. Now Mordechai Segev of the
TechnionâIsrael Institute of Technology in
Haifa and his colleagues have extended the realm of topological
insulators to include photons. They etched hundreds of helical
waveguides into a block of glass to serve as wires for light.
Because the waveguides were packed into a tight honeycomb
structure, the light in one waveguide would interfere with the
light in another and they would cancel each other out, except
along the outer edge of the waveguides. That resulted in
photons being steered to the waveguides' edges and confined to
the surface of the glass. When they reached an edge of the
glass block, the photons made the turn and continued on their
way, and none were scattered by surface imperfections. Segev's
team believes the discovery can be adapted for optical
transmission technology to increase data transfer
capabilities.
