Innocenzo De Marco

Random numbers play a crucial role in information technology, particularly as digital communication capacity continues to expand. Consequently, the need for secure and high-rate random number generation has become increasingly urgent. While integrated photonics technology holds promise for mass-producing optoelectronic quantum random number generators (QRNGs), there remains a challenge in developing fast, robust, and scalable solutions suitable for industrial deployment. Addressing this challenge, we present a fast QRNG solution in this study, leveraging a photonic integrated circuit (PIC) directly embedded onto a versatile electronic platform. Designed to withstand real-world applications, our PIC is packaged to align with industrial electronic assembly lines. To rigorously assess scalability and stability, these generators underwent week-long periods of continuous GHz operation. Furthermore, a QRNG was integrated into a quantum key distribution system, where despite operating in an uncontrolled environment, minimal variations in physical randomness were observed over 38 days, as measured from 2.9 million histograms. Finally, we implemented a security model for the QRNGs, enabling rate adjustment to match the actual randomness content and demonstrating secure generation at 2 Gbit/s.

We propose a QKD transmitter that is able to encode qubits in two different degrees of freedom, namely polarisation and time-bin/phase, and according to different protocols, including but not limited to BB84, DPS and COW.