The first electronic circuit to replace electric current with lightwaves has been built by researchers at the University of Pennsylvania. This is a significant advance for the nascent field of “metatronics”, which should allow electronic components to become “smaller, faster and more efficient”.

By designing nano-scale structures that can interact with lightwaves – which are much smaller than the radio and microwave frequencies used in traditional electronics – the researchers were able to replicate the function of basic circuit elements such as resistors, inductors and capacitors. They also demonstrated that changing the orientation (polarisation) of the light changes the function of a metatronic circuit, giving it more flexibility than a traditional circuit.