Generation and Manipulation of Spatially Entangled Photon Pairs in Nonlinear Waveguides

Spatial encoding of photonic quantum information offers the advantage of high dimensionality, which can increase the throughput and security of quantum communication protocols. Truly secure quantum communication protocols rely on entanglement. Here we show multimode nonlinear waveguides as a viable platform for integrated generation and manipulation of transverse-mode photonic entanglement. We describe a scheme for generation of spatial entanglement and an integrated electrooptic mode converter for manipulation and verification of spatial entanglement. We numerically show that the proposed devices can be realized in potassium titanyl phosphate (KTP) platform.