Recently, the team of Hao Li and Lixing You from Shanghai Institute of Microsystems and Information Technology (SIIT), Chinese Academy of Sciences (CAS), developed an ultra-high-speed, photon-count resolvable optical quantum detector with a maximum count rate of 5GHz and photon-count resolution of 61 by utilizing sandwich-structured superconducting nanowires and multiple wires working in parallel. The related research results were published online in Photonics Research under the title Superconducting single photon detector with speed of 5 GHz and photon number resolution of 61, and selected as Editor's Choice.
In recent years, superconducting nanowire single-photon detectors have been widely used in quantum communication, optical quantum computation and verification of quantum mechanical principles due to their high efficiency, low dark count rate and excellent time resolution.
The team developed an integrated system of superconducting detectors with high efficiency, ultra-high speed and high photon count resolution. In order to ensure the lightness and reliability of the detector system, the project has built a GM mini-cooler-based cooling integrated system. The system supports 64 electrical channels and operates at a minimum temperature of 2.3 K. The detector chip integrates 64 superconducting nanowires on a distributed Bragg reflector, which improves both the photon absorption rate and the detection speed. After characterization, the nanowire preparation yield is 61/64, the detection efficiency of the system reaches 90% at 1550 nm, the maximum count rate is 5.2 GHz, and the count rate is 1.7 GHz when the detection efficiency decreases by 3 dB, and the photon number resolution is 61. The performance of this detector system is expected to support the applications of deep-space laser communication, high-rate quantum communication, and basic quantum optical experiments, etc. The research work has been supported by Science and Technology Innovation 2030 (STI 2030), and has been awarded by the National Science Foundation of China.
The research work is supported by the Science and Technology Innovation 2030 - Major Project, National Natural Science Foundation of China, Youth Innovation Promotion Association of Chinese Academy of Sciences, and Shanghai Yangfan Program.
Device structure (a), superconducting nanowires (b), device packaging (c) and cooling system (d)
