Quantum photonics covers the generation, manipulation and detection of light at the quantum level. It will enable new secure communication protocols, connect quantum computers and play a significant role in sensing and imaging for healthcare, defence and security and environmental monitoring.
NPL measures the parameters which characterise the behaviour of quantum photonic components and systems (including single-photon sources, devices and detectors). These parameters are not always directly derived from conventional units of the SI system in the same way as quantities such as acceleration, resistance or power. The quantum-optical metrics we use reflect the utility of these devices for applications such as quantum random number generators (QRNGs) and quantum key distribution (QKD). Our measurements underpin the demonstration, evaluation and commercialisation of these new quantum technologies.
We are a partner in the UK Integrated Quantum Networks (IQN) Hub. We collaborate with industrial partners (including  BT, Toshiba Europe Ltd, KETS Quantum Security Ltd), other national metrology institutes (including those in Germany, Italy and the USA), academia (the IQN Hub members and Cardiff, Loughborough and Portsmouth universities), and contribute to the work of organisations developing standards (including ETSI, CEN/CENELEC ISO/IEC) to develop measurement standards.
We provide SI-traceable measurements in the following areas:
Single-photon sources -  Measurements can be performed in the visible/near-infrared part of the spectrum; we are expanding these to cover the important telecom region. Measurements can be performed at cryogenic and ambient temperatures.
Single-photon detectors - Measurements can be performed on free-space and fibre-coupled single-photon detectors in the visible/near infrared and on fibre-coupled single-photon detectors at telecom wavelengths.
Quantum random number generators and quantum key distribution systems - RNGs and QKD systems have matured to the point where commercial products are now available. These products promise enhanced security for our digital infrastructure. Measurements can be performed on discrete-variable QKD transmitter and receiver modules to characterise parameters relevant to assessing the security of their outputs.
Quantum networks - NPL is developing a stable, metrologically characterised, quantum network for testing quantum network hardware and applications.
Find out more about single-photon detector calibration
Please contact us if you require measurements in any of these areas, or for single-/few-photon metrology in general.