This thesis describes the establishment of a new fabrication facility for the realization of annealed and reverse proton exchanged waveguides in congruent lithium niobate at Grith University{Centre for Quantum Dynamics, and their application in dierent contexts of integrated quantum photonics technologies. We demonstrated the development of an accurate numerical model for the design of waveguides in X-cut and Z-cut substrates and high quality fabrication of both quasi-phase matched quadratic nonlinear waveguides and fast electro-optic waveguide modulators. Within the context of nonlinear optical processes, we demonstrated a newly proposed method which eciently reconstruct the biphoton state produced through spontaneous parametric down-conversion by the use of only classical measurements. The validity of the method is tested by a direct comparison with photon-coincidence counting measurements in a multi-channel integrated nonlinear device fabricated in our facility. We also implemented the rst frequency conversion of 369:5 nm light {resonant with the transition of Yb+ trapped ions{ to the 1550 nm telecom wavelength range with a periodically poled waveguide fabricated by the reverse proton exchange technique. Within the context of electro-optical processes, we showed the rst active demultiplexing of single-photons emitted from a quantum dot source with a single integrated device made of a network of electro-optically tunable directional couplers.