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Practical photon counting

Nature Photonicsvolume 11page684 (2017) | Download Citation

Credit: Robert Hadfield, University of Glasgow

Superconducting single-photon detectors have emerged over the past decade as the gold standard for infrared photon counting, enabling important achievements in quantum optics, space-to-ground communication and long-range remote sensing. However, these sought after devices operate just a few degrees above absolute zero and such low temperatures are challenging to achieve outside of the laboratory. Researchers at the University of Glasgow and Rutherford Appleton Laboratory UK have now adapted a miniaturized cooler first developed for space missions to house a fibre-optic-coupled superconducting detector, provided by the Dutch start-up Single Quantum BV. The packaged system offers a detection efficiency of 10% at a wavelength of 1,310 nm. The cooling to a temperature of 4 K is achieved through the use of three cold finger stages. A first Stirling stage reduces temperature to ~170 K, a second to 20 K and finally a Joule–Thompson stage takes the device to 4 K. The convenience and capabilities of the device have been shown in a range of infrared photon-counting demonstrations, including time-of-flight ranging and dose monitoring for laser cancer treatment.

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    • Oliver Graydon


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Correspondence to Oliver Graydon.

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