Researchers at NIST are advancing several single-photon detection methods that serve as foundational standards for measuring extremely faint light across quantum and classical systems. These include superconducting sensors like transition-edge sensors (TES) and nanowire detectors (SNSPDs), frequency-based resonant circuits (MKIDs), room-temperature semiconductor sensors (SPADs), and traditional photomultiplier tubes (PMTs). All of these technologies are currently implemented in research labs, astronomical instruments, and consumer electronics, with NIST actively refining them to meet stricter performance benchmarks for future quantum infrastructure.
In simple terms, each detector works by converting a single particle of light into a measurable electrical signal when it strikes the sensor. Superconducting models require extreme cooling but offer unmatched precision in counting individual photons, while semiconductor versions operate at room temperature and are already built into smartphones for imaging and distance sensing. These tools will directly enable breakthroughs in quantum networking, secure data transmission, deep-space observation, and medical diagnostics. While many systems are actively used today, researchers expect continued improvements over the next several years to fully integrate optimized detectors into scalable quantum computing and communication networks.
Source: https://www.nist.gov/quantum-information-science/quantum-sensing-explained/seeing-bits-light
Keywords: single-photon detectors, superconductivity, photon counting