TU Vienna has managed to turn the oscillation direction of
beams of light – simply by applying an electrical current to a special
material. This way, a transistor can be built that functions with light instead
of electrical current.
Light can oscillate in different directions, as we can see
in the 3D cinema: Each lens of the glasses only allows light of a particular oscillation
direction to pass through. However, changing the polarization direction of
light without a large part of it being lost is difficult. The TU Vienna has now
managed this feat, using a type of light – terahertz radiation – that is of
particular technological importance. An electrical field applied to an
ultra-thin layer of material can turn the polarisation of the beam as required.
This produces an efficient transistor for light that can be miniaturised and
used to build optical computers.