Artistic view of an integrated photonic circuit. Pulses of light, consisting of photons, are channelled through various nanoscale optical devices. Whether active or passive, these light-conducting devices - photonic band gaps, beamsplitters, interferometers, optical delay lines, resonators, optical (de)multiplexers – are key enablers of tomorrow's generations of optical processors which will be used to enhance today's generations of traditional, electron-based circuits.