However, as these components are shrunk ever further, fundamental limits to their dimensions are dictated by the wavelength of light itself. Now researchers at ETH Zurich claim to have overcome this limitation by creating both the world's smallest optical switch using a single atom, and accompanying circuitry that appears to break the rules by being smaller than the wavelength of the light that passes through it.

The exponential growth of data and its accompanying reception and transmission around the world, has meant that the severe bandwidth limitations of copper-based networks have been largely eschewed in favor of high-capacity optical systems. And, as more and more photonics-based electronic devices and processors come on line, almost all conventional wiring will follow suit and eventually be replaced by optical fibers, waveguides, and other light-carrying conduits. Some future connecting devices, however, will still require the conversion of electrical signals to light, as do current data transmission systems, and it is one of these interim components – the modulator – that researchers at ETH Zurich are seeking to miniaturize.