Tommaso Bertapelle

A wide range of applications require, by hypothesis, to have access to a private and genuine random source. Quantum Random Number Generators (QRNGs) are currently the sole technology capable of producing true randomness. Nevertheless, other factors must be considered when addressing real-world use cases, and the bulkiness of current implementations significantly limits their adoption. In this work, we present a high-performance source-device independent QRNG leveraging a custom-made integrated silicon photonic chip. The proposed scheme exploits the properties of a heterodyne receiver to enhance security and integration to promote spatial footprint reduction while simplifying its implementation. Such characteristics could represent a significant advancement toward the development of generators better suited to meet the demands of portable and space applications. Indeed, the system can deliver secure random numbers at a rate greater than 20 Gbps with a reduced encumbrance.

We present a versatile hybrid encoder for quantum key distribution that supports both discrete variable (DV) and continuous variable (CV) protocols. The encoder, based on an iPOGNAC modulator, utilizes commercial off-the-shelf components and can be reconfigured for efficient polarization modulation in DV protocols or polarization-independent phase modulation in CV protocols. This innovative design enhances flexibility, enabling the selection of the most efficient protocol based on link parameters. We experimentally realized the proposed device and tested it with both DV and CV receivers to demonstrate its performance.