### Résumé

The thesis is divided into two parts: The first part is in the field of Quantum Cryptography. In this part we develop a theoretical study of a Quantum Key Distribution (QKD) protocol in the scenario of a satellite-ground station link. We consider the addition of quantum channel fluctuations and the possibility of success of the protocol in the framework of continuous variables in an implementation with state-of-the-art technologies. We show the feasibility of CVQKD in the satellite context. In the second part, we build, from scratch, a source of continuous-variable graph-like quantum states of light using nonlinear waveguides. These states are essential for the implementation of communication and quantum computing protocol as they can be seen to be quantum networks. We perform a theoretical study for multimode quantum states of light after the interaction in a non-linear waveguide that help us to design the experiment. Finally we present the experimental results that demonstrate the first results on the quantum source of continuous variable multimode quantum states of light, measuring up to 11 squeezed thermal light states.

Publication

Quantum Optics Systems for Long-Distance Cryptography and Quantum Networks

The thesis is divided into two parts: The first part is in the field of Quantum Cryptography. In this part we develop a theoretical study of a Quantum Key Distribution (QKD) protocol in the scenario of a satellite-ground station link. We consider the addition of quantum channel fluctuations and the possibility of success of the protocol in the framework of continuous variables in an implementation with state-of-the-art technologies. We show the feasibility of CVQKD in the satellite context. In the second part, we build, from scratch, a source of continuous-variable graph-like quantum states of light using nonlinear waveguides. These states are essential for the implementation of communication and quantum computing protocol as they can be seen to be quantum networks. We perform a theoretical study for multimode quantum states of light after the interaction in a non-linear waveguide that help us to design the experiment. Finally we present the experimental results that demonstrate the first results on the quantum source of continuous variable multimode quantum states of light, measuring up to 11 squeezed thermal light states.