These components were then be used to fabricate more complicated circuits such as multi-photon entangling gates as well as core components used for fully reconfigurable quantum circuits, where reconfigurability can achieved using both thermal and electro-optic phase shifters. Another area of research in which integrated optics will prove pivotal in its development is Quantum communication and has been marked by extensive experimental development demonstrating, for example, quantum key distribution (QKD), quantum teleportation, quantum relays based on entanglement swapping, and quantum repeaters. Since the birth of integrated quantum optics experiments have ranged from technological demonstrations, for example integrated sources and integrated detectors, to fundamental tests of nature, new methods for quantum key distribution, and the generation of new quantum states of light. It has also been demonstrated that a single integrated device is sufficient to implement the full field of linear optics. As the field has progressed new quantum algorithms have been developed which provide short and long term routes towards the demonstration of the superiority of quantum computers over their classical counterparts. Cluster state computation is now generally accepted as the approach that will be used to develop a fully fledged quantum computer. Whilst development of quantum computer will require the synthesis of many different aspects of integrated optics, boson sampling seeks to demonstrate the power of quantum computation via technologies readily available and is therefore a very promising near term algorithm to doing so. In fact shortly after its proposal there were several small scale experimental demonstrations of the boson sampling algorithm  Control over photons can be achieved with integrated devices that can be realised in different material platforms such as silica, silicon, gallium arsenide, lithium niobate and indium phosphide and silicon nitride. Two methods for using silica:   2. Direct write - only uses single material and laser (use computer controlled laser to damage the glass and user lateral motion and focus to write paths with required refractive indices to produce waveguides). This method has the benefit of not needing a clean room. This is the most common method now for making silica waveguides, and is excellent for rapid prototyping. It has also been used in several demonstrations of topological photonics. The main challenges of the silica platform are the low refractive index contrast, the lack of active tunability post fabrication (as opposed to all the other platforms) and the difficulty of mass production with reproducibility and high yield due to the serial nature of the inscription process. Recent work has shown the possibility of dynamically reconfiguring these silica devices using heaters, albeit requiring moderately high power.