Continuous variable quantum information protocols with squeezed light

In this thesis, we present the generation of optical continuous variable quantum states single-mode squeezed vacuum and the entangled two-mode squeezed vacuum. We give both the theoretical fundamentals of the generation of squeezed light in optical parametric oscillators and present experimental implementation of squeezed light in a couple of different platforms. We qualify the degrees of squeezing generated and discuss the advantages and disadvantages of the different types of OPOs.
We present an experimental implementation of a measurement-device-independent protocol for verification of entanglement with the generated two-mode squeezed vacuum state. The protocol means that users can verify the existence of the entangled state by relying only on their ability to generate coherent states and not trusting the measurement device itself. We also present an experimental implementation of a measurement device independent memory certification that similarly only relies on coherent states. These implementations are the first experimental implementations of both entanglement and memory verification in continuous variables. One area of interest for such protocols could be a network in which some parties control the complicated quantum resources, such as measurements, entanglement generation and optical memories, and users which wants to use the resources but do not trust the party in control of the resources.
We also present an experiment that attempted to generate and distribute a secure quantum key between four users in a network. Unfortunately, we were not able to achieve a positive key rate mainly due to unknown sources of loss and noise in the experiment. If achieving a positive key rate the four users would be able to pairwise generate a secret key for use in sharing confidential information. Finally, we also discuss a protocol that could be used to achieve an advantage over a classical protocol in the task of reading a digital memory. We discuss the regimes of parameters in which the quantum protocol shows an advantage and the possibility of achieving an advantage experimentally.