Generation and manipulation of photonic states for quantum communication

The work presented in this thesis is mainly divided into two part. In a first experimental part, experimental realisations based on guided-wave and integrated optical solutions are implemented in the continuous-wave as well as the picosecond pulsed regimes at a telecom wavelength. The motivation behind this part is to develop experimental solutions and techniques enabling real field implementations of quantum communication protocols. The second part consists in theoretically investigating already existing as well as novel approach for high quality and high amplitude non-Gaussian quantum state generation with relatively reasonable resources. In the experimental part, three realizations are presented. The first one consists in the generation of Schrödinger cat-like state in continuous-wave regime at a telecom wavelength in a guided-wave approach based on off-the-shelf fiber components. A second realization consists in the design and the experimental characterization of an guided-wave SPDC-based source for the generation of high quality discrete and continuous-variable quantum states as well as hybrid entanglement. Finally, in the third experimental work we perform the first characterizations of low-losses and high quality factor silicon nitride micro-ring resonators for multimode entanglement generation in Kerr frequency comb. These experimental implementations are conducted with the goal of moving towards out-of-the-laboratory applications of quantum communication protocols. On the other hand, two main studies are conducted within the theoretical part. At first, we develop a theoretical framework to describe photon subtraction operation from a multimode quantum resource. Applying this framework to the case of Schrödinger cat-like state production, we show that high quality non-Gaussian states can be obtained with reasonable non-mode-selective solutions in the multimode regime. Then, we propose a novel protocol for the generation of high amplitude non-Gaussian state based on the multiplexing capabilities offered by the state-of-the-art photonic sources, drastically reducing the complexity and increasing the performances compared to previously proposed iterative protocols.