October 6, 2014

Nanoparticles Break the Symmetry of Light




Nanoparticles can emit light into ultra-thin glass fibres. Physicists at the Vienna University of Technology have now managed to select the direction of the light using an unusual kind of coupling between spin and the direction of propagation.

How can a beam of light tell the difference between left and right? At the Vienna University of Technology (TU Wien) tiny particles have been coupled to a glass fibre. The particles emit light into the fibre in such a way that it does not travel in both directions, as one would expect. Instead, the light can be directed either to the left or to the right. This has become possible by employing a remarkable physical effect – the spin-orbit coupling of light. This new kind of optical switch has the potential to revolutionize nanophotonics. The researchers have now published their work in the journal “Science”.