Invitation To Tender Upgrade of SNSPD System

Descriptions

The National Physical Laboratory [NPL] requirement is to upgrade its existing SNSPD system which is used for quantum photonics metrology. The upgrade will make use of NPL's existing cryostat, and provide 4 detectors to cover the spectral range from 600 nm to 950 nm (the spectral region where single-photon emission from NV- centres, 2D materials and quantum dots occur), plus 4 detectors to cover the 1310 nm - 1550 nm telecom bands (important for quantum communications and single-photon emission). NPL wishes be able to add up to 8 detectors at a later date; the upgrade shall provide the electrical feedthroughs required for these detectors, and not preclude (e.g. by limiting space) the addition of these detectors. Testing of high-speed QKD systems requires detectors with low jitter, as well as low after-pulsing and dark-count rates and high detection efficiency. Low jitter and high detection efficiency is also essential to characterise prospective single- and entangled-photon sources. 4 channels are required for 4-fold coincidence measurements to determine photon-number statistics.