Superconducting single-photon detectors have emerged over the past decade as the gold standard for infrared photon counting, enabling ground-breaking studies in quantum optics, space-to-ground communication and remote sensing. These sought after devices operate at a chilly -269°C. Such temperatures, just a few degrees above absolute zero, are challenging to achieve outside of the research laboratory.

In a letter in Superconductor Science and Technology, Dr Nathan Gemmell from the University of Glasgow, UK, and co-workers report a major advance in miniaturized cooling for superconducting detectors. A compact closed-cycle cooler developed by Rutherford Appleton Laboratory, UK, for space missions has been adapted to house a fibre-optic coupled superconducting detector, provided by the Dutch start-up Single Quantum BV.

Dr Gemmell explains "we have used this compact platform to carry out a range of infrared photon counting demonstrations, including time-of-flight ranging and dose monitoring for laser cancer treatment." Superconductor Science and Technology Editor-in-Chief Dr Cathy Foley of CSIRO, Australia, adds "This is a very exciting report and a genuine breakthrough. This work shows that advances in cryogenic engineering will enable superconducting detectors to have decisive impact in a host of real-world applications."