Thin film has 'astonishing' ability to rotate light Apr 4, 2011
5 comments Physicists in Austria and Germany have taken the
Faraday effect to a new extreme by rotating the polarization of
light by 45° by passing it through an extremely thin film. This
"giant Faraday effect" could someday be used to create optical
transistors that switch light or to improve terahertz imaging
systems. Discovered in 1845 by Michael Faraday, the Faraday
effect describes how a magnetic field shifts the polarization of
light as the light passes through a medium. A material's ability
to rotate light is defined by its Verdet constant – the amount
of rotation given per tesla of magnetic field strength and per
metre of material. The previous record for the strongest Faraday
effect was the semiconductor indium-antimony, which has a Verdet
constant of about 104 radians per tesla per metre. Now Andrei
Pimenov and colleagues at the Vienna Institute of Technology in
Austria and the University of Würzburg have shown that mercury-
telluride ha