Researchers at the Institute for Electromagnetic Fields at ETH Zurich have now developed an “electro-opto-mechanical” switch for light beams that is considerably smaller and faster than current models. This is relevant for applications such as self-driving cars and optical quantum technologies.
They used a magic ingredient known as “plasmonics”, where light waves are squeezed into structures that are much smaller than the wavelength of the light, which, according to the laws of optics, should be impossible to do. It can be made possible, however, by guiding the light along the boundary between a metal and a dielectric. The electromagnetic waves of the light partially penetrate the metal and cause the electrons inside it to oscillate, which results in a hybrid creature made of a light wave and an electronic excitation, the plasmon.
The scientists have already demonstrated that their new switch can be flicked on and off several million times per second with an electric voltage of little more than one volt. (SciTechDaily)