Quantum mechanics tells us how the world works at its most fundamental level. It predicts very strange behaviour that can typically only be observed when things are very cold and very small. It has an inbuilt element of chance, allows superpositions of two different states, and admits super-strong correlations between objects that would be nonsensical in our everyday world / entanglement . Despite this strange behaviour, quantum mechanics is the most successful theory that we have ever had / it predicts what will happen almost perfectly!Although the theory of quantum mechanics was invited at the beginning of the last century, quantum information science has only emerged in the last decades to consider what additional power and functionality can be realised by specifically harnessing quantum mechanical effects in the encoding, transmission and processing of information. Anticipated future technologies include quantum computers with tremendous computational power, quantum metrology which promises the most precise measurements possible, and quantum cryptography which is already being used in commercial communication systems, and offers perfect security.Single particles of light / photons / are excellent quantum bits or qubits, because they suffer from almost no noise. They also have great potential for application in future quantum technologies: schemes for all optical quantum computers are a leading contender, and photons are the obvious choice for both quantum communication and for quantum metrology schemes for measuring optical path lengths. There have already been a number of impressive proof-of-principle demonstrations of photonic information science.However, photonic quantum technologies have reached a roadblock: they are stuck in the research laboratory. All of the demonstrations to date have relied on imperfect, unscalable and bulky elements with single photons travelling in air. This is not suitable for future technologies. In addition there has been no integration of these critical components which will be essential for the realisation of scalable and practical technologies. This project aims to address these problems by developing single photon sources based on diamond nanocrystals, optical wires on optical chips, and superconducting single photon detectors, to the high performance levels required. It also aims to integrate all of these components on a single optical chip, and thus bring photonic quantum technologies out of the laboratory towards the marketplace.