Light is composed of packets of energy called photons, as recognized by Albert Einstein. Low energy photons (infrared) can travel very long distances without being strongly adsorbed or scattered by atmosphere/water when emitted in biological reactions or by astronomical objects like stars or asteroids. Hence, infrared single photon sensors are a key enabling technology in astronomy, advanced spectroscopy/diagnostics, remote sensing and imaging and also are very important in environmental monitoring and long distance (deep space) optical communication. Recently, single photon sensing has become crucial also in Photonic Quantum Information Sciences where individual photons are used to encode, manipulate and transfer information to allow for more efficient computation and potentially unconditionally secure communication.
In this talk I will show how superconducting materials allowed to realize the most sensitive single infrared photon detectors, especially superconducting nanowires single photon detectors - SNSPDs. These sensors outperformed all the other semiconducting technologies in terms spectral sensitivity, detection efficiency, timing jitter, count rate and background noise allowing to satisfy the stringent requirements of the 21st century applications. I will then briefly review the advances made in materials growth, nanopatterning techniques, design and cryogenic engineering that enabled SNSPDs to become so popular in the last decade thanks to their easiness in integration with different photonic platforms and user friendly operation. Finally, I will update on different strategies to efficiently scale up superconducting detectors in array/camera configuration, and will highlight the paralle of common challenge in quantum computing technology, to offer a step-change for users working in the field of advanced imaging, remote sensing, communication and quantum computing. These will span from the use of superconducting and semiconducting cryogenic electronics to recently proposed cryogenic optical links.