Photonics – the optical equivalent of electronics – underpins modern society. It includes the optical fibres of the internet, high-power lasers that cut and weld, and solar panels.

Prof. Robert R. Thomson of Heriot-Watt University describes some remarkable state-of-the-art applications for photonic technologies, such as cameras sensitive to – incredibly – a single photon of light, allowing us to observe it passing through thin air. In medicine new laser processing techniques allow us to cut tissues with exceptional precision, and fibre sensors will allow us to sense how diseases impact the lung tissues of critically ill patients.