Self-driving cars are becoming better and more reliable. There are a number of hurdles to be overcome before they can possibly soon be completely autonomous on the roads. Above all, the lightning-fast detection of the environment and the recognition of people and obstacles still pushes today's technologies to their limits.
Scientists led by Jürg Leuthold from the Institute for Electromagnetic Fields at ETH Zurich, together with colleagues from the National Institute of Standards and Technology (NIST) in the USA and Chalmers University in Gothenburg (Sweden), have now developed a new type of electro-optomechanical switch that can perhaps be used to elegantly solve both problems.
The magic agent used by the researchers is called plasmonics. In this technique, light waves are forced into structures that are much smaller than the wavelength of the light - which is not possible according to the laws of optics. This is however made possible by conducting the light along the boundary surface between a metal and a dielectric, i.e. an electrically weak or non-conductive substance such as air or glass. The electromagnetic waves of the light partially penetrate into the metal and excite electrons to vibrate, resulting in a hermaphrodite being of light wave and electronic excitation - the plasmon.
More than ten years ago, renowned physicists predicted that optical switches based on plasmons could herald a revolution in data transmission and processing, since both are much faster with photons than with conventional electronics. So far, however, commercial applications have failed due to the large losses caused by the transport of photons through plasmon components and the high switching voltages required.