Both academic and industrial players are looking at silicon photonics for the implementation of many quantum technologies (e.g. quantum key distribution, boson sampling, quantum gates, etc.). Indeed, the silicon photonics provides a unique combination of scalability and low losses that is needed to transform small-scale laboratory-experiments into disruptive technologies. However, the implementation of many quantum technologies requires the detection of single photons, usually with extreme challenges in terms of detection efficiency and timing jitter.
Today, the Superconducting Nanowire Single-Photon Detector (SNSPD) provides the best combination of performance. Some examples of hybrid integration in a silicon photonic platform have also been demonstrated. However, these detectors are operated at cryogenic temperatures (1 – 3 K) with obvious drawbacks in terms of cost, complexity and scalability.
Being operated at (close to) room temperature, silicon Single-Photon Avalanche Diodes (SPADs) may represent the key to make quantum technologies widely available and to bring them out of the lab. While SPADs can potentially be integrated in a silicon photonics platform they are currently coupled with silicon photonics chips through bundle of fibers.
In this presentation I will discuss the operation, the design and the state of the art of silicon SPADs. I will analyze their use in combination with silicon photonics chips and the path toward the integration of SPADs in a silicon photonics platform.