Wigner reconstruction of the quantum states emitted by a semiconductor laser: Experiments and simulations

Continuous-variable (CV) quantum communication is a crucial technology for the secure transmission of quantum information, leveraging the principles of quantum mechanics. Unlike discrete-variable (DV) approaches, which rely on the generation, manipulation, and detection of single photons, CV systems can exploit standard telecommunication technologies—such as coherent laser sources and homodyne detectors—ensuring compatibility with existing optical-communication infrastructure. One possible way to encode information in CV systems is through squeezed states, characterized by reduced uncertainty in one field quadrature with respect to the other, usually generated via complex nonlinear processes. This work focuses on the implementation of an experimental technique for the quantum tomography of these states through the reconstruction of their Wigner function.