A 100-pixel photon-number-resolving detector unveiling photon statistics

Single-photon detectors are ubiquitous in quantum information science and quantum sensing. They are key enabling technologies for numerous scientific discoveries and fundamental tests of quantum optics. Photon-number-revolving detectors are the ultimate measurement tool of light; however, few detectors so far can provide high-fidelity photon number resolution at few-photon levels. Here we demonstrate an on-chip detector that can resolve up to 100 photons by spatiotemporally multiplexing an array of superconducting nanowires along a single optical waveguide. The unparalleled photon number resolution paired with the high-speed response exclusively allows us to unveil the quantum photon statistics of a true thermal light source at an unprecedented level, which is realized by direct measurement of the higher-order correlation function g((N)) (with values of N up to 15), observation of photon-subtraction-induced photon number enhancement and quantum-limited state discrimination against a coherent light source. Our detector provides a viable route towards various important applications, including photonic quantum computation and quantum metrology.

Automated summary

Single-photon detectors play a crucial role in quantum information science and quantum sensing. However, few detectors have achieved high-fidelity photon number resolution at few-photon levels. In this study, we present an on-chip detector that can resolve up to 100 photons by spatiotemporally multiplexing an array of superconducting nanowires. Our detector enables unprecedented quantum photon statistics measurements and has potential applications in photonic quantum computation and quantum metrology.