This photograph shows two beams of UV light focused and overlapped to write optical circuitry directly into glass on the surface of a planar chip. The wavelength and intensity of the laser beams at the focus increase the local refractive index of the glass due to photosensitivity. This method of fabricating planar lightwave circuits is being explored at the Optoelectronics Research Centre, Southampton, for creating the building blocks of quantum computers, optical sensors and telecommunications. —Sam A. Berry, Optoelectronics Research Centre, uni_southampton #Quantum #WorldQuantumDay