Quantum Optics and Photon Counting

Linear SPAD array for quantum communication

Alfonso Incoronato, Fabio Severini, Francesca Madonini, Federica Villa, Franco Zappa

Published Apr 13, 2021• 4 citations

Abstract

Quantum communication is a fast-growing field that takes advantage of the quantum physics laws to protect and secure sensitive data. This work takes part of the European project UNIQORN (Affordable Quantum Communication for Everyone: Revolutionizing the Ecosystem from Fabrication to Application) whose aim is to develop a Quantum System on Chip (QSoC) for telecom application. The Integrated Circuit (IC) designed contributes in the QRNG block of the system, tailored to communicate with the integrated non-linear optics circuit. Such detector is a 32×1 linear array based on Single-Photon Avalanche-Diode (SPAD) detectors for the generation of a raw random number, by revealing the position on the array of the single photon impinging on it, realized in a BCD 0.16 μm technology. The linear array architecture consists of 32 pixels, pitched at 125 μm, each made by 4 SPADs with different diameter (5 μm, 10 μm, 20 μm, 50 μm). Two operation modes are implemented: Single-Hit Mode, needed to reveal the (5-bit) position of the pixel triggered by a single photon, representing a random number, in a time window synchronous with the laser emission. Multi Hit Mode, used to identify a coincidence of a certain number of photons(more than one, two, three or four) detected within a specified time window, thanks to a multi threshold coincidence detection logic.

DOI: 10.1117/12.2592091

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