In quantum communication, Photonic Integrated Circuits (PICs) are foreseen to be critical elements in the near-term deployment of metropolitan quantum-key-distribution-based secure systems. Individual and entangled photons can be generated, modulated and routed on the PIC. The existing use of PIC components and functionalities for wavelength division multiplexed networks can be leveraged to enable practical quantum communication.
In quantum computing, photons can be used for the encoding of qubits. PICs can be used for ultra-low loss, large-scale scalable linear optical circuits for routing processing and analysis. The available nonlinearities can be utilized for photon pair generation.